dynamics of the major plinian eruption of samalas in 1257 a d lombok indonesia the 1257 a d caldera forming eruption of samalas lombok indonesia was recently associated with the largest sulphate spike of the last 2 ky recorded in polar ice cores it is suspected to have impacted climate both locally and at a global scale extensive fieldwork coupled with sedimentological geochemical and physical analyses of eruptive products enabled us to provide new constraints on the stratigraphy and eruptive dynamics this four phase continuous eruption produced a total of 33 40 km3 dense rock equivalent dre of deposits consisting of i 7 9 km3 dre of pumiceous plinian fall products ii 16 km3 dre of pyroclastic density current deposits pdc and iii 8 9 km3 dre of co pdc ash that settled over the surrounding islands and was identified as far as 660 km from the source on the flanks of merapi volcano central java widespread accretionary lapilli rich deposits provide evidence of the occurrence of a violent phreatomagmatic phase during the eruption with a peak mass eruption rate of 4 6 108 kg s a maximum plume height of 43 km and a dispersal index of 110 500 km2 the 1257 a d eruption stands as the most powerful eruption of the last millennium eruption dynamics are consistent with an efficient dispersal of sulphur rich aerosols across the globe remarkable reproducibility of trace element analysis on a few milligrammes of pumiceous tephra provides unequivocal evidence for the geochemical correlation of 1257 a d proximal reference products with distal tephra identified on surrounding islands hence we identify and characterise a new prominent inter regional chronostratigraphic tephra marker

archaeological implications of a widespread 13th century tephra marker across the central indonesian archipelago abstract despite the occurrence of exceptionally large eruptions in the indonesian archipelago in recent historic times i e krakatoa 1883 tambora 1815 no historic tephra beds have been widely identified in the terrestrial realm that could facilitate the correlation of equivalent aged sequences and or archaeological remains this study has identified one such tephra bed of 13th century age that can be correlated throughout central east java and now can be unequivocally correlated with the samalas 1257 a d tephra recently described from lombok the occurrence of this historic tephra marker extending 650 km west from its eruptive source provides the first opportunity to effect inter regional correlation over large swathes of central indonesia it remains entirely conceivable that in the aftermath of this exceptionally large eruptive event there was considerable westward disruption to subsistence agriculture and trade food shortages and famine dislocation of affected populations and socio political unrest on a scale that equalled or exceeded the catastrophic effects documented from the more recent tambora 1815 a d eruption indeed the effects of this mid 13th century eruption can be registered globally in a variety of records from antarctica europe middle east and the americas unfortunately archaeological evidence indicating such disruption in mid 13th century indonesia is yet to be deciphered from the so far sparse accounts and inscriptions of that time however this paucity of evidence does not diminish the utility of this widespread tephra bed as a unique chronostratigraphic marker for archaeological studies across large areas of central indonesia

purple haze combined geochemical and pb sr isotope constraints on colourants in celtic glass abstract the composition of 2977 late prehistoric glass objects was investigated to derive information on the nature of the colourants used 2673 late iron age celtic la tene bracelet fragments from the netherlands and austria and 51 early iron age beads from the netherlands were analysed hand held xrf analyses demonstrated that all glass objects were of the soda silica lime type which has a presumed origin in the eastern mediterranean copper was used as colourant in the form of copper filings in most of the early iron age glass beads to give recycled glass a blue green colour the vast majority 98 of the translucent iron age glass was coloured using cobalt blue manganese purple colourless antimony colourless and iron green manganese however was added to all glass contributing additional amounts of elements like copper cobalt and iron opaque decorations were produced using antimony or a combination of tin and lead ree analyses on a selection of representative objects indicate that the manganese ores in translucent glass are of hydrogenetic diagenetic early iron age or hydrothermally influenced diagenetic late iron age types strontium isotope ratios show mixing between a calcite related seawater source 0 709 and manganese ores with isotope ratios of 0 70766 lead isotope ratios are dominated by colourant derived pb the isotope ratios of the manganese used to produce translucent glass and lead used for opaque glass decorations fall in the same range the most likely general provenance of both lies on lavrion or the western cycladic islands although an origin in the central taurus or the sinai mountains cannot be excluded the conclusion is that manganese ore used for colourants contributes significantly to the ree concentration in the glass including nd as well as to sr and pb this needs to be taken into account when using concentrations or isotope ratios of these elements for provenancing other raw materials like sand and calcium carbonate this appears to be the case for all antique soda lime silica glass

volcanic conduit controls on effusive explosive transitions and the 2010 eruption of merapi volcano indonesia abstract individual volcanoes can produce both effusive and explosive eruptions a transition between these two eruption styles dramatically changes the hazards and can occur either between distinct eruption events or within one eruption episode the causes of these transitions are difficult to determine due to the number of system parameters that can influence whether or not magma fragments in a runaway process we apply a numerical model of magma ascent in a volcanic conduit to isolate and test the effects of key parameters related to magma rheology and system geometry we find that for a given volcanic system parameters that control magma viscosity such as initial water mass fraction initial crystal volume fraction and temperature have the greatest influence on whether or not magma fragments during ascent and erupts explosively we also define a critical condition for the full set of initial parameters under which a transition in eruption style from effusive to explosive or the reverse is more likely to occur under these conditions small heterogeneities in the water or crystal content of the magma or small perturbations to the conduit pressure gradient due to magma chamber overpressure or dome growth or collapse can disrupt the magmatic conditions and cause a transition in eruption style the 2010 vei 4 eruption of merapi volcano included both effusive and explosive phases and was larger by an order of magnitude than its eruptions during the previous century we constrain our model for the merapi system using published literature values and show that between the previous eruption in 2006 and the 2010 eruption the shallow magmatic system at merapi reached critical conditions due to the ascent from depth of a large hotter more volatile rich magma under these critical conditions and according to our model results small changes in the volatile content of the magma small dome collapses subtle changes in degassing rate or the addition of co2 to the magma through decarbonation of the bedrock are all feasible mechanisms for triggering rapid transitions between effusive and explosive activity during the 2010 eruption period

provenance of polychrome and colourless 8th 4th century bc glass from pieria greece a chemical and isotopic approach abstract glass objects from pydna and methoni in modern day greece dated to the eighth to fourth century bc were chemically investigated the combined use of multiple analytical techniques allowed the elemental and isotopic characterization of these polychrome and colourless glass artefacts in order to examine their provenance all fragments were found to be soda lime silica natron based glass produced from a rather pure silica rich sand containing sea shells and mixed with natron possibly coming from more than one source based on the strontium and neodymium isotopic signatures most glass artefacts likely derive from a syro palestinian production site although the exact location is unknown also the oxygen isotopic signature of most of the samples suggests the manufacturing of the artefacts from raw materials with a primary origin along the syro palestinian coast nevertheless the use of particular raw materials cannot be excluded for some artefacts as some samples show enriched 18 o values pointing to a different glassmaking tradition

lessons learned from the 2010 evacuations at merapi volcano abstract the rapid onset and large magnitude of the 2010 eruption of merapi posed significant challenges for evacuations and resulted in a peak number of almost 400 000 internally displaced persons idps a pre existing hazard map and an evacuation plan based on the relatively small magnitude of previous eruptions of the 20th century were utilized by emergency officials during the initial phase of the eruption 25 october 3 november 2010 however when the magnitude of the eruption increased greatly on 3 5 november 2010 the initial evacuation plan had to be abandoned as danger zones were expanded rapidly and the scale and pace of the evacuation increased dramatically fortunately orders to evacuate were communicated quickly through a variety of communication methods and as a result many thousands of lives were saved however there were also problems that resulted from this rapid and larger than expected evacuation and there were lessons learned that can improve future mass evacuations at merapi and other volcanoes we analyzed the results of 1969 questionnaires and conducted a series of interviews with community leaders and emergency officials results were compiled for periods both during and after the 2010 eruption our results show that 1 trust in the indonesian government and volcanologists was very high after the eruption 2 multiple modes of communication were used to relay warnings and evacuation orders 3 50 to 70 of idps returned to the danger zone during the crisis despite evacuation orders 4 preparation before the eruption was critical to the successes and included improvements to roads and education programs 5 public education about hazards and evacuation protocols before the eruption was focused in the perceived highest danger zone where it was effective yet confusion and loss of life in other areas demonstrated that education programs in all hazard zones are needed to prepare for larger than normal eruptions and 6 improvements in registration of evacuees in providing for livestock and in activities and work programs in evacuation camps as well as government restrictions and policy changes are also needed to prevent evacuees from returning to their homes during the crisis period

the behavior of cu zn and pb during magmatic hydrothermal activity at merapi volcano indonesia abstract understanding the behavior of cu zn and pb in magmatic hydrothermal systems is essential in developing models for the genesis of hydrothermal ore deposits in subduction environments a commonly held view is that the metals originate in magmas of intermediate to felsic composition from which they partition directly into exsolving aqueous fluids in this paper we build on the results of an earlier study in which we showed that fe cu co and ni at merapi volcano indonesia were transferred from a mafic melt to an immiscible sulfide melt and then to a magmatic volatile phase which carried them to the surface here we examine the pathways taken by the volatile phase and the behavior of cu zn and pb in the upper part of the magmatic system beneath merapi volcano based on the composition of a suite of silicate melt inclusions and thermodynamic modeling we show that the mafic melt did not hybridize with the resident felsic melt but instead transferred metals to the latter by exsolving a magmatic volatile phase which dissolved the cu rich sulfide melt and then percolated upwards through the felsic melt enriching it in cu and pb it is this fluid which transported the metals to the surface and potentially also to subsurface environments of ore formation

the formation and failure of natural dams of the numerous kinds of dams that form by natural processes dams formed from landslides glacial ice and late neoglacial moraines present the greatest threat to people and property landslide dams form in a wide range of physiographic settings the most common types of mass movements that form landslide dams are rock and debris avalanches rock and soil slumps and slides and mud debris and earth flows the most common initiation mechanisms for dam forming landslides are excessive rainfall and snowmelt and earthquakes landslide dams can be classified into six categories based on their relation with the valley floor type i dams 11 of 184 landslide dams from around the world that we were able to classify do not reach from one valley side to the other type ii dams 44 span the entire valley floor in some cases depositing material high on opposite valley sides type iii dams 41 move considerable distances both upstream and downstream from the landslide failure type iv dams 1 are rare and involve the contemporaneous failure of material from both sides of a valley type v dams 1 also are rare and are created when a single landslide sends multiple tongues of debris into a valley and forms two or more landslide dams in the same reach of river type vi dams 3 involve one or more failure surfaces that extend under the stream or valley and emerge on the opposite valley side many landslide dams fail shortly after formation in our sample of 73 documented landslide dam failures 27 of the landslide dams failed less than 1 day after formation and about 50 failed within 10 days over topping is by far the most common cause of failure the timing of failure and the magnitude of the resulting floods are controlled by dam size and geometry material characteristics of the blockage rate of inflow to the impoundment size and depth of the impoundment bedrock control of flow and engineering controls such as artificial spill ways diversions tunnels and planned breaching by blasting or conventional excavation glacial ice dams can produce at least nine kinds of ice dammed lakes the most dangerous are lakes formed in main valleys dammed by tributary glaciers failure can occur by erosion of a drainage tunnel under or through the ice dam or by a channel over the ice dam cold polar ice dams generally drain supraglacially or marginally by downmelting of an outlet channel warmer temperate ice dams tend to fail by sudden englacial or subglacial breaching and drainage late neoglacial moraine dammed lakes are located in steep mountain areas affected by the advances and retreats of valley glaciers in the last several centuries these late neoglacial dams pose hazards because 1 they are sufficiently young that vegetation has not stabilized their slopes 2 many dam faces are steeper than the angle of repose 3 these dams and lakes are immediately downslope from steep crevassed glaciers and near vertical rock slopes and 4 downstream from these dams are steep canyons with easily erodible materials that can be incorporated in the flow and increase flood peaks the most common reported failure mechanism is overtopping and breaching by a wave or series of waves in the lake generated by icefalls rockfalls or snow or rock avalanches melting of ice cores or frozen ground and piping and seepage are other possible failure mechanisms natural dams may cause upstream flooding as the lake rises and downstream flooding as a result of failure of the dam although data are few for the same potential energy at the dam site ownstream flood peaks from the failure of glacier ice dams are smaller than those from landslide moraine and structed earth fill and rock fill dam failures moraine dam failures appear to produce some of the largest downstream flood peaks for potential energy at the dam site greater than 1011 1012 joules differences in flood peaks natural dam failures appear to be controlled by dam characteristics and failure mechanisms

evaluation of the impact of the 2010 pyroclastic density currents at merapi volcano from high resolution satellite imagery field investigations and numerical simulations the 2010 pyroclastic density currents pdc at merapi have presented a rare opportunity to collect a uniquely detailed dataset of the source extent lateral variations and impact of various pdc deposits on a densely populated area using traditional volcanological field based methods and a multi temporal dataset of high resolution satellite imagery a total of 23 pdc events have been recognized including 5 main channeled flows 15 overbank flows derived from overspill and re channelization of the main pdcs into adjacent tributaries and two main surge events the 2010 pdc deposits covered an area of 22 3 km2 unequally distributed between valley filling 6 9 overbank 22 4 and surge and associated fallout deposits 71 7 their total estimated non dre volume is 36 3 106 m3 with 50 2 of this volume accounting for valley filling deposits 39 3 for overbank deposits and 10 5 for surge and associated fallout deposits more than 70 of the total volume was deposited during the third eruptive phase 4 5 november and only 16 6 11 5 and 0 9 during the first 26 29 october second 30 october 3 november and fourth phase 6 23 november respectively the internal architecture and lithofacies variations of the 2010 pdc deposits were investigated using data collected from 30 stratigraphic sections measured after one rainy season of erosion the results show that complex local scale variations in flow dynamics and deposit architectures are apparent and that the major factors controlling the propagation of the main flows and their potential hazards for overbanking were driven by 1 the rapid emplacement of several voluminous pdcs associated with the steady infilling of the receiving landscape after the two first phases of the eruption 2 longitudinal changes in channel capacity following increased sinuosity in the valley and decreased containment space and 3 the effects of varying source mechanisms gravitational dome collapse vertical or lateral dome explosions and column collapse and source materials involved during individual pdc forming events integration of these data into numerical simulations of the channeled and overbank pdcs of the third eruptive phase 4 5 november using two well established geophysical mass flow models titan2d and volcflow allow us to evaluate the ability of these models to reproduce the main features of the natural deposits and some of the flow overbanking processes observed in the field using such a multi technique approach the dataset obtained in this study not only characterizes the pdcs and related hazards at merapi but will allow comparisons with similar events at other volcanoes around the globe

volcanic hazards from bezymianny and bandai type eruptions major slope failures are a significant degradational process at volcanoes slope failures and associated explosive eruptions have resulted in more than 20 000 fatalities in the past 400 years the historic record provides evidence for at least six of these events in the past century several historic debris avalanches exceed 1 km3 in volume holocene avalanches an order of magnitude larger have traveled 50 100 km from the source volcano and affected areas of 500 1500 km2 historic eruptions associated with major slope failures include those with a magmatic component bezymianny type and those solely phreatic bandai type the associated gravitational failures remove major segments of the volcanoes creating massive horseshoe shaped depressions commonly of caldera size the paroxysmal phase of a bezymianny type eruption may include powerful lateral explosions and pumiceous pyroclastic flows it is often followed by construction of lava dome or pyroclastic cone in the new crater bandai type eruptions begin and end with the paroxysmal phase during which slope failure removes a portion of the edifice massive volcanic landslides can also occur without related explosive eruptions as at the unzen volcano in 1792 the main potential hazards from these events derive from lateral blasts the debris avalanche itself and avalanche induced tsunamis lateral blasts produced by sudden decompression of hydrothermal and or magmatic systems can devastate areas in excess of 500km2 at velocities exceeding 100 m s 1 the ratio of area covered to distance traveled for the mount st helens and bezymianny lateral blasts exceeds that of many pyroclastic flows or surges of comparable volume the potential for large scale lateral blasts is likely related to the location of magma at the time of slope failure and appears highest when magma has intruded into the upper edifice as at mount st helens and bezymianny debris avalanches can move faster than 100 ms 1 and travel tens of kilometers when not confined by valley walls avalanches can affect wide areas beyond the volcano s flanks tsunamis from debris avalanches at coastal volcanoes have caused more fatalities than have the landslides themselves or associated eruptions the probable travel distance l of avalanches can be estimated by considering the potential vertical drop h data from a catalog of around 200 debris avalanches indicates that the h l rations for avalanches with volumes of 0 1 1 km3 average 0 13 and range 0 09 0 18 for avalanches exceeding 1 km3 h l ratios average 0 09 and range 0 5 0 13 large scale deformation of the volcanic edefice and intense local seismicity precede many slope failures and can indicate the likely failure direction and orientation of potential lateral blasts the nature and duration of precursory activity vary widely and the timing of slope faliure greatly affects the type of associated eruption bandai type eruptions are particularly difficult to anticipate because they typically climax suddenly without precursory eruptions and may be preceded by only short periods of seismicity

magmatic hydrothermal evolution and devolatilization beneath merapi volcano indonesia abstract at merapi volcano indonesia explosive eruptions lasting several months result from injections of reduced mafic magmas and are interspersed by periods of lava dome growth and collapse quiescent degassing assimilation of wall rock and fractional crystallization lasting a few years silicate melt inclusions and volcanic gases were analyzed to study processes of magmatic volatile exsolution and volcanic degassing during periods of quiescent degassing at merapi volcanic gases were sampled at merapi in 1994 during a phase of quiescent degassing and in 2006 at the end of a dome growth and collapse explosive eruption silicate melt inclusions were collected and analyzed from lavas and scorias for their major element and volatile components solubility relationships between h 2 o and co 2 in melt inclusions demonstrate that melt was being trapped beneath merapi to depths reaching 19 km host amphibole geobarometry indicates crystallization pressures reaching up to 26 km hence there is evidence of deep pooling and crystallization of magma beneath merapi at appreciable depths using a mass balance model of magmatic volatile exsolution we demonstrate that the magma degassing from 19 km to the surface approaches closed system behavior compared to the bulk magmatic volatiles analyzed in melt inclusions volcanic gases had similar amounts of co 2 were enriched in h 2 o and s and depleted in cl and f we thus propose that the magmatic volatile phase was initially exsolved from the magma as a supercritical fluid and that it subsequently exsolved into a h 2 o cl f rich brine and co 2 s rich vapor according to the h 2 o nacl model brine vapor exsolution occurred at 5 km in depth for a 5 wt nacl 900 c to 1000 c fluid although the presence of h 2 s so 2 and co 2 may cause the supercritical fluid to unmix at greater depths magma at shallower depths exsolved a brine and a vapor directly from the melt the volcanic gases at merapi thus represent the vapor fraction of a magmatic volatile phase as brine ponded below the surface we further suggest that carbon dioxide liberated by the magmatic assimilation of limestone as proposed by other studies fluxed the melt thereby promoting co 2 enrichment of the melt and h 2 o degassing finally we propose that merapi volcanic gases are enriched in sulfur compared to the modeled volatile phase composition because deep reduced mafic magma supplies sulfur to the shallow magmatic plumbing system

palaeochannels of the balkh river northern afghanistan and human occupation since the bronze age period in 2002 the unexpected discovery of hellenistic architectural blocks buried in 8 m of alluvium found displaced in a former bed of the river of balkh brought about a programme of surveys and excavations under the aegis of the french archaeological mission in bactria the geoarchaeological side of the programme focused on the drawing of a regional geomorphological map then on the identification mapping and dating of the palaeochannels of the river of balkh we established the chronology of several fluvial channel generations by association with archaeological settlements of different eras bronze age bactro achaemenid period kushan period islamic period and with optically stimulated luminescence dating carried out on alluvium deposits the present riverbed leading up to aqcha was formed during the islamic period we suspect the primary agent of this change in the river channel to be tectonic activity and the activation of a blind fault crossing the floodplain we identified a northern bactro achaemenid aqueduct currently located in the desert area separating the plain of balkh from the amu darya

pleistocene glaciations of central asia results from 10be surface exposure ages of erratic boulders from the pamir tajikistan and the alay turkestan range kyrgyzstan abstract we have determined the timing of glaciations in the pamir tajikistan and the alay turkestan range kyrgyzstan using 10be surface exposure dating glacial advances in the area have occurred 93 136 60 80 40 55 27 25 22 20 19 17 16 15 15 13 and 11 9 cal ka bp all late pleistocene glaciers in the pamir and the alay turkestan ranges have been valley glaciers except for the most extended glaciers on the pamir plateau which have formed local piedmont glaciations in the eastern pamir these are characterized by ela depressions of 370 380 m thar 0 5 in the turkestan range and alay range ela depressions at the same time were 750 and 600 m respectively late pleistocene glacier advances all over western high asia were contemporaneous with climatic cold phases rather than monsoonal maxima their maximum extent and that of the western hemisphere ice sheets were asynchronous due to increasing aridity in the region over the course of the last glacial late pleistocene climate in central asia seems to have been influenced by the interplay of the westerly circulation and the siberian anticyclone some indirect monsoonal influence in the eastern pamir may be responsible for the existence of some of the lateglacial moraine stages in this area high altitude glaciers seem to have reached their maximum extent earlier mis 5 4 than low altitude glaciers first half of mis 3 possibly due to prolonged glacial aridity imparting with moisture advection onto high altitude sites inducing glacial retreat but prolonged cold during the same time imparting with glacier ablation at lower altitude sites inducing glacial advance

equilibrium line altitudes of the last glacial maximum for the himalaya and tibet an assessment and evaluation of results abstract contemporary equilibrium line altitudes elas for glaciers in the high mountains of the himalaya and tibet have considerable variation because the region is influenced by two major climatic systems the mid latitude westerlies and the south asian summer monsoon and glaciers are subject to strong topographic controls reconstructions of past elas based on the former extent of glaciers are numerous but were estimated using a variety of methods some of which are not appropriate for high altitude glaciers which are strongly influenced by topography and have extensive supraglacial debris cover furthermore few of the reconstructions have adequate chronological control because of the difficulty of dating glacial landforms in high altitude regions where organic matter for radiocarbon dating is sparse or absent cosmogenic radionuclide surface exposure and optically stimulated luminescence dating are providing data to define the timing of glaciation and these together with objective analysis of glacier dynamics may allow better estimates of ela changes in the future however there are currently only two regions the hunza valley and the khumbu himal which are sufficiently well dated to allow reconstructions of last glacial maximum glacier extent and hence elas these two regions cannot provide an adequate assessment of ela changes for the himalayan tibetan region

micro dynamics and macro patterns exploring new archaeological data for the late holocene human water relationship in the murghab alluvial fan turkmenistan in this article we re visit hypotheses about the changing social and environmental landscapes in southern central asia during the late holocene specifically giving attention to the transitional period between the archaeologically defined late bronze early iron age second half of the 2nd millennium bc and the numerous documented changes in the archaeological and physio geographical record during this time we focus on the northeastern murghab alluvial fan turkmenistan as a window into this complex period and examine one aspect of human environmental dynamics there namely the relationship between the location of archaeological sites and mapped ancient watercourses palaeochannels through time our analysis incorporates nearly 400 new archaeological sites documented in the northeastern murghab since 2006 which have not previously been included in published models of settlement and or hydrological dynamics our findings suggest the periods of the late bronze age and early iron age yaz i demonstrate two distinct access to water practices which may correlate to different processes of socio territorial control being implemented while no single line of evidence can adequately disentangle the complex interconnected processes of environmental and social change our results lend themselves to integration with the current working knowledge of the local processes of socio environmental development in the murghab the results also fit more broadly within emerging discourse that recognizes the importance of micro scale processes and adaptation in eurasian prehistory

toward a revised hazard assessment at merapi volcano central java abstract of 1 1 million people living on the flanks of the active merapi volcano 440 000 are at relatively high risk in areas prone to pyroclastic flows surges and lahars for the last two centuries the activity of merapi has alternated regularly between long periods of viscous lava dome extrusion and brief explosive episodes at 8 15 year intervals which generated dome collapse pyroclastic flows and destroyed part of the pre existing domes violent explosive episodes on an average recurrence of 26 54 years have generated pyroclastic flows surges tephra falls and subsequent lahars the 61 reported eruptions since the mid 1500s killed about 7000 people the current hazard zone map of merapi pardyanto et al 1978 portrays three areas termed forbidden zone first danger zone and second danger zone based on successively declining hazards revision of the hazard map is desirable because it lacks details necessary to outline hazard zones with accuracy in particular the valleys likely to be swept by lahars and excludes some areas likely to be devastated by pyroclastic gravity currents such as the 22 november 1994 surge in addition risk maps should be developed to incorporate social technical and economic factors of vulnerability eruptive hazard assessment at merapi is based on reconstructed eruptive history on eruptive behavior and scenarios and on existing models and preliminary numerical modeling firstly the reconstructed eruptive activity in particular for the past 7000 years and from historical accounts of eruptions helps to define the extent and recurrence frequency of the most hazardous phenomena newhall et al 2000 camus et al 2000 pyroclastic flows traveled as far as 9 15 km from the source pyroclastic surges swept the flanks as far as 9 20 km away from the vent thick tephra fall buried temples in the vicinity of yogyakarta 25 km to the south and subsequent lahars spilled down the radial valleys as far as 30 km to the west and south at least one large edifice collapse has occurred in the past 7000 years newhall et al 2000 camus et al 2000 secondly four eruption scenarios are portrayed as hazardous zones on two maps and derived from the past eruptive behavior of merapi and from the most affected areas in the past thirdly simple numerical simulation based on a digital elevation model a stereo pair of spot satellite images and one 2d orthoimage helps to simulate pyroclastic and lahar flowage on the flanks and in radial valley channels and to outline areas likely to be devastated three major threats are identified 1 a collapse of the summit dome in the short to mid term that can release large volume pyroclastic flows and high energy surges towards the south southwest sector of the volcano 2 an explosive eruption much larger than any since 1930 may sweep all the flanks of merapi at least once every century 3 a potential collapse of the summit area involving the fumarolic field of gendol and part of the southern flank which can contribute to moderate scale debris avalanches and debris flows

the association of lava dome growth with major explosive activity vei 4 domehaz a global dataset investigation of the global eruptive records of particular types of volcanoes is a fundamental and valuable method of understanding what style of activity can be anticipated in the future and can highlight what might be expected or unusual in particular settings this paper investigates the relationship between large explosions volcanic explosivity index vei 4 and lava dome growth from 1000 ad to present and develops the domehaz database domehaz contains information from 397 dome forming episodes including duration of dome growth duration of pauses in extrusion extrusion rates and the timing and magnitude vei of associated large explosions major explosive activity when associated with dome growth is more likely to occur before dome growth rather than during or at the end of dome forming eruptions in most cases where major explosive activity has been associated with dome growth the eruptions occurred at basaltic andesite to andesitic volcanoes the most common type of dome forming volcano but a greater proportion of dacitic and rhyolitic dome growth episodes were associated with large explosions high extrusion rates 10 m3 s 1 seem to be associated with large explosions and may inhibit degassing or destabilize existing domes leading to explosive decompression large explosions may alternatively be followed by dome growth which represents the clearing of residual magma from the conduit relationships extracted from the global record can be used to construct probability trees for new and ongoing dome forming eruptions or can be used in conjunction with other types of event trees to aid in forecasting volcanic hazards during a crisis especially for volcanoes where data are sparse

deformation and seismic precursors to dome collapse and fountain collapse nuees ardentes at merapi volcano java indonesia 1994 1998 abstract following the eruption of january 1992 episodes of lava dome growth accompanied by generation of dome collapse nuees ardentes occurred in 1994 1998 in addition nuees ardentes were generated by fountain collapse in january 1997 and the 1998 events also suggest an explosive component significant tilt and seismic precursors on varying time scales preceded these events deformation about the summit has been detected by electronic tiltmeters since november 1992 with inflation corresponding generally to lava dome growth and deflation or decreased inflation corresponding to loss of dome mass strong short term days to weeks accelerations in tilt rate and seismicity occurred prior to the major nuees ardentes episodes apart from those of 22 november 1994 which were preceded by steadily increasing tilt for over 200 days but lacked short term precursors because of the combination of populated hazardous areas and the lack of an issued warning about 100 casualties occurred in 1994 in contrast the strong precursors in 1997 and 1998 provided advance warning to observatory scientists enabled the stepped raising of alert levels and aided hazard management as a result of these factors but also the fortunate fact that the large nuees ardentes did not quite descend into populated areas no casualties occurred the nuee ardente episode of 1994 is interpreted as purely due to gravitational collapse whereas those of 1997 and 1998 were influenced by gas pressurization of the lava dome

joint inversion of active and passive seismic data in central java seismic and volcanic activities in central java indonesia the area of interest of this study are directly or indirectly related to the subduction of the indo australian plate in the framework of the merapi amphibious experiments meramex a network consisting of about 130 seismographic stations was installed onshore and offshore in central java and operated for more than 150 days in addition 3 d active seismic experiments were carried out offshore in this paper we present the results of processing combined active and passive seismic data which contain traveltimes from 292 local earthquakes and additional airgun shots along three offshore profiles the inversion was performed using the updated lotos 06 code that allows processing for active and passive source data the joint inversion of the active and passive data set considerably improves the resolution of the upper crust especially in the offshore area in comparison to only passive data the inversion results are verified using a series of synthetic tests the resulting images showan exceptionally strong low velocity anomaly 30 per cent in the backarc crust northward of the active volcanoes in the upper mantle beneath the volcanoes we observe a low velocity anomaly inclined towards the slab which probably reflects the paths of fluids and partially melted materials in the mantle wedge the crust in the forearc appears to be strongly heterogeneous the onshore part consists of two high velocity blocks separated by a narrow low velocity anomaly which can be interpreted as a weakened contact zone between two rigid crustal bodies the recent java mw 6 3 earthquake 2006 05 26 utc occurred at the lower edge of this zone its focal strike slip mechanism is consistent with the orientation of this contact

the 2006 lava dome eruption of merapi volcano indonesia detailed analysis using modis tir abstract merapi is one of indonesia s most active and dangerous volcanoes prior to the 2010 vei 4 eruption activity at merapi during the 20th century was characterized by the growth and collapse of a series of lava domes periods of very slow growth were punctuated by short episodes of increased eruption rates characterized by dome collapse generated pyroclastic density currents pdcs an eruptive event of this type occurred in may june 2006 for effusive eruptions such as this detailed extrusion rate records are important for understanding the processes driving the eruption and the hazards presented by the eruption we use thermal infrared tir images from the moderate resolution imaging spectrometer modis instrument on nasa s aqua and terra satellites to estimate extrusion rates at merapi volcano during the 2006 eruption using the method of harris and ripepe 2007 we compile a set of 75 nighttime modis images of the eruptive period to produce a detailed time series of thermal radiance and extrusion rate that reveal multiple phases of the 2006 eruption these data closely correspond to the published ground based observational record and improve observation density and detail during the eruption sequence furthermore additional analysis of radiance values for thermal anomalies in band 21 3 959 m of modis images results in a new framework for detecting different styles of activity we successfully discriminate among slow dome growth rapid dome growth and pdc producing dome collapse we also demonstrate a positive correlation between pdc frequency and extrusion rate and provide evidence that extrusion rate can increase in response to external events such as dome collapses or tectonic earthquakes this study represents a new method of documenting volcanic activity that can be applied to other similar volcanic systems

the first archaeometric data on polychrome iron age glass from sites located in northern italy abstract a large sample set of transparent and opaque glass artefacts recovered from etruscan contexts in northern italy bologna and spina fe necropoleis and dated to a period between the 6th and 4th century bc are analysed in this paper samples of highly decorated beads spindle whorls and vessels of the mediterranean group i alabastron oinochoes amphoriskos were selected in order to determine whether these different glass artefacts were produced at the same manufacturing site while the vessels almost certainly originate from greece the beads could derive from a more ancient local production ascertained at the site of frattesina rovigo italy and dated to the bronze age the aims of this study are i to characterise a set of iron age glass artefacts thus providing new quantitative chemical data and ii to identify possible differences between finds recovered from different localities and between glass vessels and beads in order to establish whether different manufactures were active contemporaneously the chemical analyses of major and minor elements were performed with an electron microprobe the nature of the opacifying and colouring agents was determined by x ray diffraction the sample set is relatively homogeneous and most of the samples can be classified as low magnesium glass the yellow opaque decorations are rich in pb and sb while only sb is present in the white and light blue samples the xrd analyses confirmed the presence of lead antimonates in the yellow decorations and of calcium antimonates in the white and light blue decorations

the 1984 nuee ardente deposits of merapi volcano central java indonesia stratigraphy textural characteristics and transport mechanisms for many centuries merapi volcano has generated hot avalanches of blocks lapilli and ashes derived from the destruction of partially solidified viscous lava domes merapi type nuees ardentes on 15 june 1984 at least four nuees ardentes came down the southwest slope of the merapi the first and the last being responsible for more than 99 of the deposits which are now exposed the first nuee ardente a merapi type nuee ardente was produced by the destruction of the dome travelled 7 km from the crater leaving a measured deposit 2 7 m thick 4 km from the crater near its upper depositional limit regularly increasing to a maximum measured thickness of 12 m at the front of the deposit the lower contact is sharp non erosive with pines still rooted in the underlying paleosol the deposit consists of 50 ash 33 lapilli and 17 blocks with two subpopulations one rosin and one normal and is finespoor with less than 4 of fine ash d finer than 4 the deposit displays reverse population grading of both vesiculated and massive clasts and of the maximum grain size the maximum size significantly increases regularly down current over most of the exposed length of unit 1 and bed thickness increases for the entire length of the deposit the deposit of the second nuee ardente is only 6 21 cm thick and of very limited lateral extent it is a normally graded coarse to fine ash with a finespoor base the third unit consists of fines poor normally graded coarse ash exposed in low amplitude 20 40 cm 12 m wavelength dunes the deposit of the fourth nuee ardente rests in sharp erosive contact on the underlying unit increasing in thickness down flow it consists of transitional coarse and fine grained strata 6 130 c cm thick dipping 5 10 down flow the deposit made up of two subpopulations one rosin and one normal is normally graded over the entire bed but coarsegrained strata are reversely graded the relative content of vesiculated clasts increases up bed in both strata types from 12 at the base to 40 at the top the characteristics of unit 1 suggest that it accumulated from a concentrated suspension of cohesionless solids exhibiting non newtonian behavior where dispersive pressure played an important role in the suspension of the clasts units 2 and 3 were probably deposited from dilute turbulent suspensions whereas the upper unit 4 is a classic example of deposition from a high density turbulent suspension leading to the formation of multiple traction carpets driven by the overlying lower density surge the horizontal distance travelled by a hot rock avalanche may be influenced by its transport mechanism debris flows are mobile on very low slopes as low as 1 whereas grain flows even density modified grain flows require relatively high slopes more than 6 at merapi to maintain their mobility if the present merapi dome were to collapse and produce a debris flow its present volume coupled with the minimal 1 5 km vertical drop could travel a distance ranging between 15 and 30 km however if transport were by grain flow mechanisms the mass could come to rest as it reaches a 5 10 slope

the eastern flank of the merapi volcano central java indonesia architecture and implications of volcaniclastic deposits abstract merapi volcano in central java island is considered to be the most active and dangerous andesitic volcano in indonesia the volcanic history of merapi volcano is complex and often perturbed by frequent episodes of eruptive edifice building and subsequent erosion and collapse in this paper we present a detailed field literature and gis study of the well preserved eastern flank of merapi which has been spared from major eruptions in order to reconstruct the geologic and geomorphic history of the edifice here the most recent deposits arise from the remobilization of the old volcanic materials by lahar gravitational collapse of massive lava flow and local landslide processes in this study we describe the specific deposits and subsequent alteration and removal processes the stratigraphic analysis was performed with respect to the distinct phases of construction due to eruptions and dismantling of the volcano by erosion gravitational collapse and the associated local to distal re sedimentation based on gis analysis and field surveys a drainage network anomaly was detected in two main rivers the soka and the brambang rivers we infer that an apex fan of volcaniclastic material was deposited into a central paleo pusur river and explains the abnormal divergence of the rivers a new lithological 3d conceptual model is proposed based on the characterization of the lithological facies and their temporal and spatial evolution along the eastern flank of merapi volcano

nuees ardentes of 22 november 1994 at merapi volcano java indonesia nuees ardentes associated with dome collapse on 22 november 1994 at merapi volcano traveled to the south southwest as far as 6 5 km and collectively accumulated roughly 2 5 3 million cubic meters of deposits the damaged area comprises 9 5 km2 and is covered by two nuee ardente facies a conventional merapi type valley fill block and ash flow facies and a pyroclastic surge facies the proximal deposits reflect the accumulation of dozens of nuees ardentes with many subsidiary flow units the distal deposits are more simply organized as only a few individual events reached to distances 3 5 km the stratigraphic relationships north of turgo hill indicate that the surge deposits are a facies of particularly mobile nuees ardentes that also deposited channeled block and ash flow facies they further suggest that the surge facies beyond the channel margins correlate laterally with a finer grained sublayer locally developed at the base of the block and ash flow facies eyewitness reports suggest that the emplacement of the block and ash flow facies in the distal part of the boyong river may have followed by a short time interval the destruction and deposition of the surge facies at turgo village the stratigraphy is in accord with the eyewitness reports the surge facies was emplaced by a dilute surge current detached from the same dome collapse nuee ardente that as a separate flow unit subsequently emplaced the distal block and ash deposit in the boyong valley the detachment occurred at higher elevations likely at or above the slope break at about 2000 m elevation this flow separation enabled the surge current to shortcut over the landscape and to emplace its deposit even as the block and ash flow continued its tortuous southward movement in the boyong channel dome collapse nuee ardente activity formed the bulk of the eruption which was accompanied by virtually no significant vertical summit explosive activity

tephrochronology petrology and geochemistry of late holocene pyroclastic deposits from volcan de colima mexico abstract volcan de colima in western mexican volcanic belt is the most active volcano in north america we present a detailed tephrochronological study of its holocene proximal tephra fall pyroclastic surge and pyroclastic flow deposits based on 98 new stratigraphic sections 183 new dendrocalibrated radiocarbon 14 c age determinations 209 new geochemical analyses of pumice and ash 50 texture and mineral point counting mode determinations and 230 grain size analyses these results provide a much clearer understanding of the explosive eruptive behavior of volcan de colima during the past 10 000 years our data reveals that only one of the many eruptions described in historic documents has been large enough to be preserved we discuss the major and trace element geochemistry and petrology of the holocene tephra and compare it with the currently erupting calc alkaline andesites and alkaline minettes and basanites from the adjacent cinder cones it appears that several of the oldest 12 000 6000 yrs bp samples of the holocene tephra may record the last episodes of calc alkaline and alkaline magma mixing as first described in the pioneering work of luhr and carmichael 1981 finally the tephrochronological record from the northern downwind side of the colima volcanic complex is compared with the extensive radiocarbon constrained record of holocene debris avalanche deposits on the south side of the complex to build a more integrated picture of its past volcanic activity

quaternary landscape evolution in the eastern hindu kush pakistan abstract the eastern hindu kush in northern pakistan is among the most dynamically active tectonic and geomorphic areas in the world during the quaternary valley fill sediments of great thickness have been deposited by glacial fluvial eolian and mass movement processes fluvial incision eroded these sediments and formed terraces their development was controlled by tectonic and climatic factors and therefore they record information about the quaternary landscape evolution and glaciations investigations included the mapping of landforms especially the terraces and sedimentological analyses on valley fill deposits this resulted in a classification with six main types of terraces morainic glaciofluvial fluvial lacustrine mass movement debris and fan terraces tectonic terraces were not recognized but tectonically influenced sediments have been found near the shyok suture zone this classification corresponds with results from the nearby karakoram two major late pleistocene glaciations are recognized during marine isotopic stage 3 mis 3 drosh glacial stage and in the mis 2 early holocene pret glacial stage moraines from the neoglacial shandur glacial stages i and ii and the little ice age barum glacial stage i are located near the contemporary glaciers during deglaciations huge terraces were formed the upper terrace or broz fan formation and the middle terrace or ayun fan formation between the drosh and pret glacial stages and the lower terrace or urghuch fan formation after the pret glacial stage the chronology presented in this paper shows that there was only limited glaciation in the eastern hindu kush during the global last glacial maximum lgm

studying deep sources of volcanism using multiscale seismic tomography abstract this paper presents an overview of several examples of multiscale studies of different volcanic systems including intracontinental collisional and subduction related volcanic areas regional tomographic models of the upper mantle are presented for three regions with the cenozoic intracontinental volcanism in eurasia namely europe southern siberia and eastern arctic in all cases recent volcanic fields correlate with low velocity anomalies in the mantle the modeling results show that these volcanic manifestations are related to large hot areas in the mantle and not to thin column shaped contrasted plumes as presumed by many collisional type volcanism is discussed with an example of the caucasus and the surrounding areas the regional tomographic model for this region reveals a lack of mantle lithosphere beneath the collision zone volcanism in this area is most likely due to the direct heating of the thick crust by the hot asthenosphere a dominantly felsic composition of the crust facilitates upward transport of the fluids and melts that leads to volcanic eruption subduction related volcanic systems are discussed for three different scale levels an example of a regional model of the mantle beneath the sunda arc reveals the general configuration of the slab middle scale tomographic models in areas of the toba caldera central java and central andes display feeding paths of the arc volcanoes from the slab the feeding paths are apparent in all of the considered cases but have different shapes depending on the unique features of the subduction regimes an example of a detailed local scale study of magmatic sources in the crust is discussed for the kluchevskoy volcano group it is found that the main volcano kluchevskoy is fed through a complex three layered system of magma sources another volcano of the same group bezymianny seems to be connected with the mantle through a direct short lived channel which appears only during the eruption periods a time dependent tomography study performed for this group over a period of ten years clearly reveals the correlation between the changes in the seismic structures and the stages of the volcanic process namely preparation activation and relaxation

borobudur monument java indonesia stood by a natural lake chronostratigraphic evidence and historical implications the ninth century world heritage buddhist monument of borobudur java indonesia stands above the floor of a dried out palaeolake but it remains uncertain as to whether it was ever constructed on a lake shore here we reveal through new chronological and palaeoenvironmental data on the extant sediment record of the area that borobudur intentionally stood by an existing lake for the first time evidence of this conjunction validates quite literally the debated cosmological interpretation of the edifice as an aquatic lotus symbol upon which buddha is seated the fluctuating life history of the lake spanned at least 20 000 years

ground deformation at merapi volcano java indonesia distance changes june 1988 october 1995 abstract edifice deformations are reported here for the period 1988 1995 at merapi volcano one of the most active and dangerous volcanoes in indonesia the study period includes a major resumption in lava effusion in january 1992 and a major dome collapse in november 1994 the data comprise electronic distance measurements edm on a summit trilateration network slope distance changes measured to the upper flanks and other data collected from 1988 to 1995 a major consequence of this study is the documentation of a significant 4 year period of deformation precursory to the 1992 eruption cross crater strain rates accelerated from less than 3 10 6 day between 1988 and 1990 to more than 11 10 6 day just prior to the january 1992 activity representing a general asymmetric extension of the summit during high level conduit pressurization after the vent opened and effusion of lava resumed strain occurred at a much reduced rate of less than 2 10 6 day edm measurements between lower flank benchmarks and the upper edifice indicate displacements as great as 1 m per year over the four years before the 1992 eruption the gendol breach a pronounced depression formed by the juxtaposition of old lava coulees on the southeast flank functioned as a major displacement discontinuity since 1993 movements have generally not exceeded the 95 confidence limits of the summit network exceptions to this include 12 cm outward movement for the northwest crater rim in 1992 1993 probably from loading by newly erupted dome lava and movements as much as 7 cm on the south flank between november 1994 and september 1995 no short term precursors were noted before the november 1994 lava dome collapse but long term adjustments of crater geometry accompanied lava dome growth in 1994 short term 2 cm deflation of the edifice occurred following the november 1994 dome collapse

grand sarcoui volcano chaine des puys massif central france a case study for monogenetic trachytic lava domes abstract the grand sarcoui is a prominent trachytic volcano of the intraplate quaternary volcanic field of chaine des puys massif central france which fulfills basic requirements for being qualified as monogenetic grand sarcoui looks like a simple axisymmetric lava dome but close observation reveals a complex and dissymmetric structure and composition the construction of the dome about 12 5 ka ago combined both endogenous and exogenous growth which resulted in variable modes of emplacement and textures of the lava one of its most interesting features is a large 0 29 106 m2 fan of deposits bearing hummocks and secondary hydro eruption craters cross sections of these deposits demonstrate that they originated from a sector collapse accompanied by a blast like event the dome is covered by a thin layer of lapilli and ash attributed to a delayed summit eruption which occurred about 10 6 ka ago surprisingly late after its construction so this volcano has at a reduced scale features that are more usually observed in large composite volcanoes however some of these features differ slightly from those that have been documented to date and they remain partly unexplained this shows that monogenetic well preserved trachytic lava domes are uncommon and poorly known unlike rhyolitic andesitic and dacitic domes

evaluation of geophysical mass flow models using the 2006 block and ash flows of merapi volcano java indonesia towards a short term hazard assessment tool abstract the dynamics and depositional processes associated with block and ash flows bafs are most commonly inferred to be a function of granular or inertial grain flow similar to debris flows and cold rock avalanches existing geophysical mass flow models are either based on frictional mohr coulomb behavior the titan2d model developed at the state university of new york at buffalo usa or another rheological law i e a constant retarding stress eventually adding some viscous and turbulent components the volcflow model developed at the laboratoire magmas et volcans clermont ferrand france the 2006 bafs of merapi present a rare opportunity to test these two well established models against a well constrained field example integration of high resolution field based data into numerical simulations allows the validity of these models to be tested and rapid quantification of best fit input parameters we first show that with the incorporation of spatially varying bed friction angles titan2d is capable of reproducing the paths runout distances areas covered and deposited volumes of the 2006 merapi flows over highly complex topography however some discrepancies with field data are noted and the velocity and travel time of the flows do not match entirely using a single free parameter a constant retarding stress simulations obtained with the volcflow model also reproduce the morphology and distribution of the natural deposits as well as the time of emplacement and velocities of the flows the results suggest that the performance of these models in simulating actual events is critically dependent on 1 the calibration of the model by using extensive field based data such as deposit distribution and processes of flow generation transport and deposition 2 the incorporation of a suitable numerical topographic dataset i e high resolution digital elevation model and 3 the choice of input parameters such as location and volume of the initial pile of material and source characteristics single or multiple dome collapse dome collapse duration and total volume of collapsed material sensitivity analyses and inundation maps based on the probability of impact were used to produce a suite of potentially inundated areas from future gravitational dome collapse events affecting the gendol valley and adjacent areas on the southern flank of the volcano our results provide the basis for defining hazard zonations of key areas at risk from bafs which will be generated during future comparable eruptions at merapi

palaeosecular variation in java and bawean islands indonesia during the brunhes chron summary a palaeomagnetic study has been conducted from indonesian lava flows and dykes sampling was concentrated to the merapi and merbabu volcanoes central java the bromo tengger volcanic complex the lurus volcano both east of java and the bawean island numerical dating indicates that the rock units sampled have ages that are well distributed within the brunhes chron only a few reverse polarity flows were probably emplaced during the late matuyama chron alternating field af and thermal demagnetization treatments were routinely used for all sites results from both methods were generally in good agreement demonstrating the reliability and the reproducibility of the palaeomagnetic determinations obtained from 36 independent sites the large dispersion of the directions and the age distribution indicate that a large spectrum of the secular variation has been sampled our best estimate of the mean brunhes field direction in java is characterized by a zero declination and an inclination anomaly of 4 7 with a 95 per cent confidence angle of 5 3 this value agrees with an axial dipolar field model or a model to which a persisting zonal quadrupolar term of a few per cent of the geocentric axial dipole is added this study adds new constraints to recent results which suggested that a large zone of negative inclination anomalies may have persisted in the southwestern pacific ocean over the past 500 kyr and possibly extended toward the eastern indian ocean the present results do not support such an extension they also suggest that the inclination anomaly may have varied over 100 kyr and that it was more pronounced in recent times

pyroclastic density current volume estimation after the 2010 merapi volcano eruption using x band sar abstract pyroclastic density current deposits remobilized by water during periods of heavy rainfall trigger lahars volcanic mudflows that affect inhabited areas at considerable distance from volcanoes even years after an eruption here we present an innovative approach to detect and estimate the thickness and volume of pyroclastic density current pdc deposits as well as erosional versus depositional environments we use sar interferometry to compare an airborne digital surface model dsm acquired in 2004 to a post eruption 2010 dsm created using cosmo skymed satellite data to estimate the volume of 2010 merapi eruption pdc deposits along the gendol river kali gendol kg results show pdc thicknesses of up to 75 m in canyons and a volume of about 40 106 m3 mainly along kg and at distances of up to 16 km from the volcano summit this volume estimate corresponds mainly to the 2010 pyroclastic deposits along the kg material that is potentially available to produce lahars our volume estimate is approximately twice that estimated by field studies a difference we consider acceptable given the uncertainties involved in both satellite and field based methods our technique can be used to rapidly evaluate volumes of pdc deposits at active volcanoes in remote settings and where continuous activity may prevent field observations

analysis of polychrome iron age glass vessels from mediterranean i ii and iii groups by la icp ms in this work the analytical results obtained by icp ms with laser ablation solid sampling and sem eds for some polychrome glass vessels from the iron age are presented and discussed the samples coming from etruscan sites near adria northern italy belong to the so called mediterranean groups i ii and iii and are dated from the 5th 3rd and 2nd century b c respectively to date analytical data for only two sets of vessels of the iron age have been discussed in the literature in spite of the low number of available samples this is the first time that vessels of all three periods are analytically compared elemental concentration data show that the samples can be classified as low magnesia low potash lmlk soda lime silica glasses with low phosphorus and titanium contents in agreement with data for similar samples of the same age bivariate and multivariate analyses of the contents of many elements characterizing the siliceous sands showed three distinct sets corresponding to the three periods since the sets indicate different provenances of the sands it seems rational to assume that different glassmaking locations were involved chromophores and opacifiers of the blue bodies and the yellow white and turquoise decorations of the vessels were analytically identified while the nature of the corresponding ores was hypothesized

polygenetic nature of a rhyolitic dome and implications for hazard assessment cerro pizarro volcano mexico abstract rhyolitic domes are commonly regarded as monogenetic volcanoes associated with single brief eruptions in contrast to andesitic or dacitic domes that usually show a complex evolution including alternating long periods of growth and explosive destruction rhyolitic domes are characterized by short lived successions of pyroclastic and effusive activity associated with a series of discrete eruptive events that apparently last on the order of years to decades or perhaps up to centuries cerro pizarro a rhyolitic dome in the eastern mexican volcanic belt is a relatively small 1 1 km3 isolated volcano that shows aspects of polygenetic volcanism including long term repose periods 50 80 ky between eruptions chemical variations over time and a complex evolution of alternating explosive and effusive eruptions including a cryptodome phase a sector collapse event and prolonged erosional processes this eruptive behavior provides new insights into how rhyolite domes may evolve in contrast to the traditional models of rhyolitic domes as short lived monogenetic systems a protracted complex evolution bears important implications for hazard assessment if reactivation of an apparently extinct rhyolitic dome must be seriously considered

landscape development preceding homo erectus immigration into central java indonesia the sangiran formation lower lahar abstract the sangiran dome is the primary stratigraphic window for the solo basin a coastal feature on the pliocene pleistocene sunda subcontinent south margin in the dome the lower lahar unit llu is a lahar type debris flow overlying near shore marine sediments the event that emplaced the llu likely originated from sector collapse on a neighboring volcanic edifice freshwater mollusc fossils in the llu indicate that swamps or shallow lakes lay between the edifice and the current dome area 40ar 39ar analyses on hornblende separates from six pumice lenses suggest that the llu was deposited as early as 1 90 0 02 ma the event resulting in deposition of the llu transformed late pliocene near shore marine environments into estuarine and marsh settings shortly thereafter glacioeustatic sea level falls completed the local transition to fully terrestrial environments that attracted homo erectus to southernmost sunda in the early pleistocene

reconstruction of mid holocene sedimentary environments in the central part of the thessaloniki plain greece based on microfaunal identification magnetic susceptibility and grain size analyses abstract the study aims to estimate the relative contributions of the two drainage basins of the aliakmon and axios rivers which since the mid holocene have been responsible for building the largest deltaic area in greece sediments from five cores located in the central part of the thessaloniki plain have been studied for their environmental changes using paleontological and sedimentological methods chronostratigraphical evidence was obtained from 14 c ams dating of marine shells peat and organic sediment samples during the holocene marine transgression this large coastal plain was a shallow marine bay reaching approx 35 km inland circa the 4th millennium bc from which the sea subsequently regressed to the east around the middle of the 3rd millennium bc strong fluvial deposition of aliakmon to the east and of axios to the north occurred and was responsible of a gradual change to lagoonal and limnic environmental conditions around the 5th century bc a freshwater lake occupied the westernmost part of the plain microfaunal identification together with magnetic susceptibility measurements and grain size analysis reveal three main environments of sediment deposition that reflect combinations of both concentrated and dispersed sources of magnetic source minerals using remote sensing and a combination of spectral bands landsat tm imagery we identify former fluvial levees and a freshwater lake and give a spatial interpretation of the rivers influences in building this deltaic complex the mechanisms of edification of the plain as well as the roles played by aliakmon and axios sedimentation are described

merapi 2010 eruption chronology and extrusion rates monitored with satellite radar and used in eruption forecasting abstract despite dense cloud cover satellite borne commercial synthetic aperture radar sar enabled frequent monitoring of merapi volcano s 2010 eruption near real time interpretation of images derived from the amplitude of the sar signals and timely delivery of these interpretations to those responsible for warnings allowed satellite remote sensing for the first time to play an equal role with in situ seismic geodetic and gas monitoring in guiding life saving decisions during a major volcanic crisis our remotely sensed data provide an observational chronology for the main phase of the 2010 eruption which lasted 12 days 26 october 7 november 2010 unlike the prolonged low rate and relatively low explosivity dome forming and collapse eruptions of recent decades at merapi the eruption began with an explosive eruption that produced a new summit crater on 26 october and was accompanied by an ash column and pyroclastic flows that extended 8 km down the flanks this initial explosive event was followed by smaller explosive eruptions on 29 october 1 november then by a period of rapid dome growth on 1 4 november which produced a summit lava dome with a volume of 5 10 6 m 3 a paroxysmal vei 4 magmatic eruption with ash column to 17 km altitude destroyed this dome greatly enlarged the new summit crater and produced extensive pyroclastic flows to 16 km radial distance in the gendol drainage and surges during the night of 4 5 november the paroxysmal eruption was followed by a period of jetting of gas and tephra and by a second short period 12 h of rapid dome growth on 6 november the eruption ended with low level ash and steam emissions that buried the 6 november dome with tephra and continued at low levels until seismicity decreased to background levels by about 23 november our near real time commercial sar documented the explosive events on 26 october and 4 5 november and high rates of dome growth 25 m 3 s 1 an event tree analysis for the previous 2006 merapi eruption indicated that for lava dome extrusion rates 1 2 m 3 s 1 the probability of a large 1872 scale eruption was 10 consequently the order of magnitude greater rates in 2010 along with the explosive start of the eruption on 26 october the large volume of lava accumulating at the summit by 4 november and the rapid and large increases in seismic energy release deformation and gas emissions were the basis for warnings of an unusually large eruption by the indonesian geological agency s center for volcanology and geologic hazard mitigation cvghm and their volcano research and technology development center bpptk in yogyakarta warnings that saved thousands of lives

timing and style of late quaternary glaciation in the eastern hindu kush chitral northern pakistan a review and revision of the glacial chronology based on new optically stimulated luminescence dating abstract glacial landforms and sediments provide evidence for two late quaternary major glaciations in the eastern hindu kush new optically stimulated luminescence osl dating was undertaken to define the timing of these glaciations and associated sediment deposition the drosh glacial was defined by osl dating to have occurred during marine isotopic stage 3 producing an extensive valley glaciation that extended to an altitude of 1300 m above sea level asl in the main valley with an equilibrium line altitude ela depression of 1200 m the pret glacial produced a valley glaciation that extended to an altitude of 1670 m asl in the main valley with an ela depression of 1000 m the new osl dating suggests that this glacial stage probably represents several glacial advances that occurred during the latter part of the last glacial moraines representing two minor glacial advances the shandur and barum glacial stages were also recognized near the contemporary glaciers these probably formed during the middle late holocene and little ice age respectively this study and comparisons with adjacent regions suggest that there was limited glaciation during the global last glacial maximum lgm in the hindu kush deglaciation in the mountain ranges of the himalayas and the consequent meltwater discharge into the adjacent seas was negligible immediately after the global lgm and it was therefore of minor importance as a forcing factor for global climate change during the end of the last glacial cycle however our studies show that glaciation and particularly deglaciation is important in controlling the deposition of thick valley fills and the landscape evolution of the high mountain environments

the respiratory health hazard of tephra from the 2010 centennial eruption of merapi with implications for occupational mining of deposits ashfall into heavily populated areas during the october november 2010 eruption of merapi volcano indonesia created anxiety regarding the growing impacts to health as the eruption escalated and the hazard zone widened we made a preliminary assessment of the respiratory hazards to human health of the tephra deposits ashfall lahar and pdc surge from the eruption using a laboratory protocol specifically developed to study the toxic potential of volcanic ash particles twenty samples collected from a range of locations were analysed for health pertinent mineralogical parameters grain size crystalline silica content morphology surface area bulk chemistry and leachable elements and bio reactivity hydroxyl radical generation haemolytic potential oxidative capacity pro inflammatory response the grain size pertinent to respiratory health was variable ranging from 1 4 15 6 vol sub 4 m and 3 0 28 9 vol sub 10 m diameter material no fibre like particles were observed cristobalite was present in all samples ranging from 1 9 9 5 wt but surface reactivity and in vitro toxicity assays showed low reactivity for all samples tested the risk of direct exposure to ash from fallout was in any case low due to seasonal rains limiting its re suspension and the immediate and effective clean up of communities by local people who supplied the ash to the indonesian construction industry for use as aggregate however mining of the lahar and thick pdc deposits in the valleys draining the volcano is performed on a vast industrial scale which could result in high occupational exposure to thousands of sand miners at merapi during the dry seasons further study of the health hazard of the mined merapi deposits is warranted

rain triggered lahars following the 2010 eruption of merapi volcano indonesia a major risk abstract the 2010 vei 4 eruption of merapi volcano deposited roughly ten times the volume of pyroclastic materials of the 1994 and 2006 eruptions and is recognized as one of the most intense eruption since 1872 however as the eruptive phase is now over another threat endangers local communities rain triggered lahars previous papers on lahars at merapi presented lahar related risk following small scale dome collapse pdcs thus the aim of this study is to provide new insights on lahar related risk following a large scale vei 4 eruption the paper highlights the high number of events 240 during the 2010 2011 rainy season october 2010 may 2011 the frequency of the 2010 2011 lahars is also the most important ever recorded at merapi lahars occurred in almost all drainages located under the active cone with runout distances exceeding 15 km the geomorphic impacts of lahars on the distal slope of the volcano are then explained as they directly threaten houses and infrastructures creation of large corridors avulsions riverbank erosion and riverbed downcutting are detailed through local scale examples related damage is also studied 860 houses damaged 14 sabo dams and 21 bridges destroyed sedimentological characteristics of volcaniclastic sediments in lahar corridors are presented with emphasis on the resource in building material that they represent for local communities risk studies should not forget that thousands of people are exposing themselves to lahar hazard when they quarry volcaniclastic sediment on lahar corridors finally the efficient community based crisis management is explained and shows how local people organize themselves to manage the risk 3 fatalities were reported although lahars reached densely populated areas to summarize this study provides an update of lahar risk issues at merapi with emphasis on the distal slope of the volcano where lahars had not occurred for 40 years and where lahar corridors were rapidly formed

10 000 years of explosive eruptions of merapi volcano central java archaeological and modern implications abstract stratigraphy and radiocarbon dating of pyroclastic deposits at merapi volcano central java reveals 10 000 years of explosive eruptions highlights include 1 construction of an old merapi stratovolcano to the height of the present cone or slightly higher our oldest age for an explosive eruption is 9630 60 14 c y b p construction of old merapi certainly began earlier 2 collapse s of old merapi that left a somma rim high on its eastern slope and sent one or more debris avalanche s down its southern and western flanks impoundment of kali progo to form an early lake borobudur at 3400 14 c y b p hints at a possible early collapse of merapi the latest somma forming collapse occurred 1900 14 c y b p the current cone new merapi began to grow soon thereafter 3 several large and many small buddhist and hindu temples were constructed in central java between 732 and 900 a d roughly 1400 1000 14 c y b p explosive merapi eruptions occurred before during and after temple construction some temples were destroyed and or buried soon after their construction and we suspect that this destruction contributed to an abrupt shift of power and organized society to east java in 928 a d other temples sites though were occupied by caretakers for several centuries longer 4 a partial collapse of new merapi occurred 14 c y b p eruptions 700 800 14 c y b p 12 14th century a d deposited ash on the floors of still occupied candi sambisari and candi kedulan we speculate but cannot prove that these eruptions were triggered by the same partial collapse of new merapi and that the eruptions in turn ended caretaker occupation at candi sambisari and candi kedulan a new or raised lake borobudur also existed during part or all of the 12 14th centuries probably impounded by deposits from merapi 5 relatively benign lava dome extrusion and dome collapse pyroclastic flows have dominated activity of the 20th century but explosive eruptions much larger than any of this century have occurred many times during merapi s history most recently during the 19th century are the relatively small eruptions of the 20th century a new style of open vent less hazardous activity that will persist for the foreseeable future or alternatively are they merely low level background activity that could be interrupted upon relatively short notice by much larger explosive eruptions the geologic record suggests the latter which would place several hundred thousand people at risk we know of no reliable method to forecast when an explosive eruption will interrupt the present interval of low level activity this conclusion has important implications for hazard evaluation

analysis of the seismic activity associated with the 2010 eruption of merapi volcano java abstract the 2010 eruption of merapi is the first large explosive eruption of the volcano that has been instrumentally observed the main characteristics of the seismic activity during the pre eruptive period and the crisis are presented and interpreted in this paper the first seismic precursors were a series of four shallow swarms during the period between 12 and 4 months before the eruption these swarms are interpreted as the result of perturbations of the hydrothermal system by increasing heat flow shorter term and more continuous precursory seismic activity started about 6 weeks before the initial explosion on 26 october 2010 during this period the rate of seismicity increased almost constantly yielding a cumulative seismic energy release for volcano tectonic vt and multiphase events mp of 7 5 10 10 j this value is 3 times the maximum energy release preceding previous effusive eruptions of merapi the high level reached and the accelerated behavior of both the deformation of the summit and the seismic activity are distinct features of the 2010 eruption the hypocenters of vt events in 2010 occur in two clusters at of 2 5 to 5 km and less than 1 5 km depths below the summit an aseismic zone was detected at 1 5 2 5 km depth consistent with studies of previous eruptions and indicating that this is a robust feature of merapi s subsurface structure our analysis suggests that the aseismic zone is a poorly consolidated layer of altered material within the volcano deep vt events occurred mainly before 17 october 2010 subsequent to that time shallow activity strongly increased the deep seismic activity is interpreted as associated with the enlargement of a narrow conduit by an unusually large volume of rapidly ascending magma the shallow seismicity is interpreted as recording the final magma ascent and the rupture of a summit dome plug which triggered the eruption on 26 october 2010 hindsight forecasting of the occurrence time of the eruption is performed by applying the material failure forecast method ffm using cumulative real time seismic amplitude rsam calculated both from raw records and on signals classified according to their dominant frequency stable estimates of eruption time with errors as small as 4 h are obtained within a 6 day lapse time before the eruption this approach could therefore be useful to support decision making in the case of future large explosive episodes at merapi

borobudur a basin under volcanic influence 361 000 years bp to present abstract borobudur basin is located in central java indonesia 30 km to the north of yogyakarta city the basin is famous for its unesco world heritage temple and for one of the world s most active volcanoes merapi located to the east of borobudur basin merapi is one of the three andesitic volcanoes that surround the basin merapi merbabu and sumbing volcanoes therefore volcanic activity has strongly influenced the evolution of borobudur basin the object of this contribution is to present the evolution of borobudur basin over the last 161 000 years in the light of volcanic influence the methodology and tools developed for this research span over different areas of expertise from geochemistry geology and geomorphology to remote sensing gis and archeology results highlight the following points 1 two major volcanic events deposited volcaniclastic materials up to tens of meters thick 119 000 years bp and 31 000 years bp in the southern part of the borobudur basin the second volcanic event could correspond to the collapse of the older ancient merapi camus et al 2000 or proto merapi stage newhall et al 2000 2 there is no trace in the borobudur basin of a large debris avalanche 3 there are several generations of paleolakes in the borobudur basin the latest one has shrunk until historical times corroborating the theory of newhall et al 2000 and murwanto et al 2004 that borobudur temple was standing by a water body most of these paleolakes were impounded following volcanic events paleolakes most probably originated from the blockage of the hydrographic network by volcanic material 4 borobudur temple was never buried under volcanic material during historic times

investigation of iron age north eastern scottish glass beads using element analysis with la icp ms abstract class 13 and 14 iron age scottish glass beads are a group of highly decorated beads of british origin or design dating indicatively to the 1st and 2nd century ad and typically found in aberdeenshire and moray district guido 1978 85 9 their distinctive stylistic characteristics and geographical segregation renders them ideal for the investigation of whether the glasses employed in their manufacture were imported rather than produced locally and for the assessment of the technology used in the production of the deep colours studies performed in the 1980s on different specimens pertaining to the same classes henderson 1982 showed compositional characteristics differing from iron age southern british beads suggesting a different source of glass for their manufacture here a set of 19 beads which was never investigated before was analysed for 32 major minor and trace elements using laser ablation inductively coupled plasma mass spectrometry la icp ms the sample set shows good homogeneity in major and minor element composition indicating the use of imported natron glass with standardized composition typical of roman glass of the period also reflected in the recipes used for colouration evidence for the use of cullet and waste glass was found which along with the particularity of the design suggests a local origin of the beads and possible production by native glassworkers

226ra or 226ra ba dating of holocene volcanic rocks application to mt etna and merapi volcanoes this paper shows how 226ra 230th disequilibria can be used to date holocene volcanic rocks from some well selected volcanoes a systematic study of these disequilibria on historical or well dated volcanic samples is indeed first required to test the applicability of this method two examples are described here to illustrate its potential in the case of mt etna the good correlation observed between 226ra 0 activities at the time of eruption and th contents in lava flows from the last two millennia m condomines j c tanguy v michaud magma dynamics at mt etna constraints from u th ra pb radioactive disequilibria and sr isotopes in historical lavas earth planet sci lett 132 1995 25 41 is used to infer the ages of several newly analysed lava flows the calculated ages are in good agreement with those deduced from the archaeomagnetic curve describing the variation of the geomagnetic field direction in southern italy j c tanguy i bucur j f c thompson geomagnetic secular variation in sicily and revised ages of historic lavas from mt etna nature 318 1985 453 455 j c tanguy m le goff v chillemi a paiotti c principe s la delfa g patane variation seculaire de la direction du champ geomagnetique enregistree par les laves de l etna et du vesuve pendant les deux derniers millenaires c r acad sci paris 329 1999 557 564 j c tanguy m le goff c principe s arrighi v chillemi a paiotti s la delfa g patane archaeomagnetic dating of mediterranean volcanics of the last 2100 years validity and limits earth planet sci lett 211 2003 111 124 we also present a whole set of new u series data on historical recent and older samples from merapi indonesia and show that the 226ra ba ratio has probably maintained a quasi steady state value during at least the past four millennia and can be used to infer the 226ra 0 ba ratio of old volcanics at the time of eruption and thus their ages comparison with 14c ages available on three samples r gertisser j keller temporal variations in magma composition at merapi volcano central java indonesia magmatic cycles during the past 2000 years of explosive activity j volcanol geotherm res 123 2003 1 23 shows an excellent agreement these dating methods based on the post eruptive decrease of 226ra excesses can be confidently used to date young rocks on both volcanoes an important step to infer their recent eruptive history and magmatic evolution it also opens the possibility to extend the geomagnetic field variation curve back into the past few millennia the promising results obtained in this work should encourage new systematic u series studies to test the applicability of such methods to other permanently active volcanoes showing 226ra excesses

lahars at merapi volcano central java an overview abstract merapi volcano in central java is one of the most active volcanoes in the world at least 23 of the 61 reported eruptions since the mid 1500s have produced source deposits for lahars the combined lahar deposits cover about 286 km 2 on the flanks and the surrounding piedmonts of the volcano at merapi lahars are commonly rain triggered by rainfalls having an average intensity of about 40 mm in 2 h most occur during the rainy season from november to april and have average velocities of 5 7 m s at 1000 m in elevation a wide range of facies may be generated from a single flow which may transform downvalley from debris flow to hyperconcentrated streamflow because of the high frequency and magnitude of the lahar events lahar related hazards are high below about 450 600 m elevation in each of the 13 rivers which drain the volcano hazard zone maps for lahar were produced by pardyanto et al volcanic hazard map merapi volcano central java 1 100 000 geol surv of indonesia bandung ii 4 1978 and the japanese indonesian cooperation agency master plan for land conservation and volcanic debris control in the area of mt merapi jakarta 1980 but these maps are of a very small scale to meet modern zoning requirements more recently a few large scale maps 1 10 000 and 1 2000 scale and risk assessments have been completed for a few critical river systems

morphological and structural changes at the merapi lava dome monitored in 2012 15 using unmanned aerial vehicles uavs abstract dome building volcanoes undergo rapid and profound topographic changes that are important to quantify for the purposes of hazard assessment however as hazardous lava domes often develop on high altitude volcanoes that exhibit steep sided topography it is challenging to obtain direct field access and thus to analyze these morphological and structural changes merapi volcano in indonesia is a type example of such a volcano as soon after its 2010 eruption a new lava dome developed this dome was partially destroyed during six distinct steam driven explosions that occurred between 2012 and 2014 here we investigate the topographic and structural changes associated with these six steam driven explosions by comparing close range photogrammetric data obtained before and after these explosions to accomplish this we performed two uav campaigns in 2012 and 2015 by applying the structure from motion sfm technique we are able to construct three dimensional point clouds assess their quality by comparing them to a terrestrial laser scanning tls dataset and generate high resolution digital elevation models dems and photomosaics the comparison of these two dems and photomosaics reveals changes in topography and the appearance of fractures in the 2012 dataset we find a dense fracture network striking to the nnw sse in the post eruptive 2015 dataset we see that this nnw sse fracture trend is much more strongly expressed we also detect the formation of aligned and elongated explosion craters which are associated with the removal of over 200 000 m3 of dome material most of which 70 was deposited outside the crater region therefore this study suggests that the locations of the steam driven explosions at merapi volcano were controlled by the reactivation of preexisting structures moreover some of the newly developed and reactivated fractures delineate a block on the southern slope of the dome which could become structurally unstable and potentially lead to rock avalanche hazards this study therefore demonstrates the significance of characterizing structural fingerprints during the development of lava domes and exemplifies the value of topographic and fracture mapping which is becoming increasingly feasible when using uavs even on high and steep stratovolcanoes

kinematic characteristics of pyroclastic density currents at merapi and controls on their avulsion from natural and engineered channels we herein report an example of pyroclastic density current avulsion on 14 june 2006 at merapi indonesia four discrete series of multiple dome collapses led to the generation of four individual block and ash flows into kali gendol valley all four pyroclastic density currents locally overflowed the channel margins to devastate cultivated terraces along each side of the box shaped canyon while propagating as much as 2 2 km within adjacent tributaries the largest destruction was caused by the second and third pyroclastic density currents both of these flows partially spilled out of the gendol valley at a travel distance of 4 9 km bypassing a sabo dam just upstream of the village of kaliadem and leaving the village almost completely destroyed and buried by several meters of overbank deposits the main mechanism of flow avulsion on june 14 was the overflow of up to 20 vol of the dense basal part of the pyroclastic density currents onto interfluves the relative proportions of valley escaped material increased dramatically in the succession of each of the four pyroclastic density currents the main geometric parameters controlling flow avulsion and their critical values were quantified through high resolution real time kinetic global positioning system rtk gps data of the pre event topography for each of the 14 june flows this case highlights the way in which a sabo dam can significantly increase the potential of flow avulsion key lessons are derived for the future hazard mitigation in valleys subject to volcanic mass flows flow observational and geometric data are combined into a model to derive the kinematic characteristics of the basal valley ponding avalanche and the valley escaping veneer flows which are otherwise hidden by overriding clouds of elutriated ash

insights into eruption dynamics from the 2014 pyroclastic deposits of kelut volcano java indonesia and implications for future hazards abstract on 13 to 14 february 2014 a 4 h long vei 4 eruption occurred at kelut volcano java indonesia pyroclastic density currents pdcs and extensive ash fall led to 7 fatalities and disruption to flights across the asia pacific region new sedimentological descriptions of the pyroclastic deposits from the 2014 eruption were compared with eyewitness and satellite reports to elucidate temporal variations in eruptive dynamics the stratigraphy of the deposits is presented in 3 stages associated with two eruptions that occurred approximately 15 30 min apart stage 1 pdc deposits originate from the smaller onset eruption the pdc deposits from stage 2 and tephra fall deposits from stage 3 originate from the second plinian eruption during the onset eruption stage 1 low energy pdcs were produced that ran out to 70 by vol pdc deposits ran out to 4 7 km from the vent the deposits reflect an increased output of fresh fragmented magma and some conduit widening evidenced by dense lithic fragments vent instabilities and incorporation of dense material into basal margins of the plume led to the marginal collapse and formation of these pdcs stage 3 occurred in the final hour at the peak of the plinian eruption around 01 00 to 02 00 and produced reversely graded lapilli fall deposits with 90 vol pumice from a 26 km high plume this indicates that there was a sustained flux of juvenile magma to the now open vent system and expansion and fragmentation of the gas rich magma was at its most efficient our study of the eruptive sequence of kelut provides some constraints on predicted patterns for future explosive activity critical for further hazard assessment of the volcano since 1901 kelut has erupted on intervals of 1 to 23 years and the 2014 event characterises a typical explosive style of eruption that alternates regularly with effusive dome formation and collapse events this pattern depends on the dynamics of magma renewal to the system and degassing conditions in the shallow magma reservoir and upper conduit if this pattern holds and the next eruption occurs within the next two decades a return of prolonged dome growth could be anticipated

signs of magma ascent in lp and vlp seismic events and link to degassing an example from the 2010 explosive eruption at merapi volcano indonesia the link between seismicity and degassing is investigated during the vei 4 eruptions of merapi volcano indonesia in october and in early november 2010 seismicity comprised a large number and variety of earthquakes including volcano tectonic events a sustained period of long period seismicity lps i e long period events lp very long period events vlp and tremor lps seismicity is ascribed to the excitation of fluid filled cavity resonance and inertial displacement of fluids and magma we investigate here lps that occurred between 17 october and 4 november 2010 to obtain insights into the volcano eruption processes which preceded the paroxysmal phase of the eruption on 4 5 november we proceed to the moment tensor inversion of a well recorded large vlp event during the intrusion phase on 17 october 2010 i e before the first explosion on 26 october by using two simplified models crack and pipe we find a shallow source for this vlp event at about 1 km to the south of the summit and less than 1 km below the surface we analyze more than 90 lp events that occurred during the multi phase eruption 29 october 4 november we show that most of them have a dominant frequency in the range 0 2 4 hz we could locate 48 of those lp events at least 3 clusters of lp events occurred successively we interpret these observations as generated by different fluid filled containers in the summit area that were excited while magma rose we also observe significant variations of the complex frequency during the course of the eruption we discuss these changes in terms of a variable ratio of fluid to solid densities and or by possible conduit geometry change and or permeability of the conduit or the edifice and or by resonance of different fluid containers during the release of more than 0 4 tg of so2 and large but unknown masses of other volcanic gases finally we also discuss how the major explosions of the eruption were possibly triggered by passing waves resulting from regional tectonic earthquakes on 3 and 4 november

organic block coatings in block and ash flow deposits at merapi volcano central java the 1954 1994 1998 and 2006 block and ash flow deposits from merapi volcano indonesia contain andesite blocks that display localized dark surface coatings these coated blocks are typically found in clusters but may also occur isolated within the block and ash flow deposits the coatings form irregular patches tens of centimetres across on block surfaces and are characterized by a silver metallic appearance the origin and composition of the coatings have not previously been determined and no comparable deposits have been described in detail from any other volcanically active region of the world carbon isotope analyses of coated and uncoated bulk rock material and of a range of charred and uncharred wood samples suggest that the dark block coatings at merapi volcano are organic in origin scanning electron microscopy and reflected light microscopy indicate that such coatings may form due to the migration and subsequent deposition of organic carbon in cavities within the andesite blocks the most recent field evidence from the 2006 block and ash flow deposits at merapi indicates that in situ charcoalification of plant material after block deposition and or during the final stages of flow is the major mechanism that forms localized concentrations of block coatings isolated coated blocks may result either from recycling of older deposits or more likely from charcoalification and redistribution of plant material caught between colliding lava blocks during flow

volcano tectonic control of merapi s lava dome splitting the november 2013 fracture observed from high resolution terrasar x data abstract volcanism at active andesite dacite volcanoes is often associated with the formation and collapse of circular shaped protrusions of extruded highly viscous lava the so called domes which are emplaced in the near summit region growing domes may experience stable and instable structural phases with a gradual transition in between dome collapse and the break off of instable blocks of viscous lava may lead to pyroclastic flows one of the most lethal hazards at stratovolcanoes at merapi volcano indonesia a new dome started growing in the summit region in the amphitheater formed in the course of the climactic 2010 eruption three years later the dome reached a height of approximately 100 m and diameters of 220 and 190 m with a plateau like surface area of 40 000 m2 approximately on 18 11 2013 an explosion occurred without identified precursors leaving a major fracture cutting the complete dome structure based on high resolution terrasar x satellite radar imagery we could identify the linear fracture traceable over 200 m in the long axis up to 40 m wide after geocoding of the radar amplitude imagery the fractures azimuthal trend could be compared to other structural lineaments indicative of a significant nnw sse structural direction that has formed on merapi volcano in the past the merapi dome fractured in a nw se direction and is consistent with the alignment of regional tectonic structures and of anticipated directions of pyroclastic flows the fracture may be part of a larger volcano tectonic system and may affect the dynamics and the stability of the merapi dome

boundary crossing and non linear theory in earth system sciences a proof of concept based on tsunami and post eruption scenarios on java island indonesia although volcanic eruptions are well known to be the trigger of some weather and climatic changes land cover changes by pyroclastic flows and lahars do not get this recognition neither do major hazards such as tsunami these two earth processes are even lesser considered as being able to modify other earth processes they are not directly connected to such as landslides or river discharge in non connected basins more than a hundred kilometres away in this contribution the authors argue that these ideas are mainly driven by the process of being educated in a single academic discipline and once put to the test interactions and retroactions between earth processes and atmospheric processes are far more reaching than commonly thought for this study the site of java island indonesia was chosen to conduct 1 an analysis of a major tsunami impact in the same area as the 2006 java tsunami and 2 an analysis of the post eruption impacts of merapi volcano after a major eruption excluding any ejecta in the atmosphere for the sake of the demonstration the atmospheric feedback simulations were conducted using the regional climate model regcm 4 with calibration from weather stations in java island as a result both simulations have proven that large scale deposits of pyroclasts not introducing the ejectas sent in the atmosphere and tsunamis can have outstanding impacts on the atmospheric situation and the bio geomorphologic evolution of the landscape in the following weeks to months interestingly enough these impacts are not limited to the area impacted by the earth process and the effect are not linear in time as they work following thresholds these rainfalls tele impacts are important enough to in turn modify earth surface processes in areas remote from the original phenomenon this system acts in the same manner as a famous butterfly in africa that could trigger a hurricane on the other side of the atlantic ocean copyright 2012 john wiley sons ltd

internal structure of mount merapi indonesia derived from long offset transient electromagnetic data 1 a long offset transient electromagnetic lotem survey was carried out on merapi volcano indonesia in 1998 lotem data have been recorded at 41 receiver locations which cover a 10 km w e and a 15 km s n profile the signals were transmitted at four locations on the south west and north sides of merapi the data were interpreted with one dimensional 1 d inversions in addition two particular features were investigated with 3 d modeling on the south flank the magnetic field data show strong 3 d distortions consistently over the profile which can only be explained by a conductive near surface structure like a fracture filled with conductive fluids the simulation of topographic effects shows that the interpretation is not significantly affected on both profiles the most striking feature is a conductive layer of 20 m at depths of 500 1000 m below the surface and a thickness of 1 2 km the cause of the increased conductivity may be different for the summit area the intermediate zone and at the flanks below the summit in vicinity of the conduit the decrease in resistivity is produced either by hydrothermal fluids by partial melts or rocks altered by the hydrothermal system or by a combination in the intermediate zone between the conduit and the flanks either alteration or hydrothermal fluids may be the source of the conductivity increase fluids seem to be the most likely cause for the conductive layer at the flanks and the west east striking anomaly from the resistivity of the conductive layer and the typical porosity of volcanic rock we estimate fluid resistivities of 0 2 1 m

a comparison of the landsat image and laharz simulated lahar inundation hazard zone by the 2010 merapi eruption located above the java subduction zone merapi volcano is an active stratovolcano with a volcanic activity cycle of 1 5 years most merapi eruptions are relatively small with volcanic explosivity index vei of 1 3 however the most recent eruption which occurred in 2010 was quite violent with a vei of 4 and 386 people were killed in this study lahars and pyroclastic flow zones were detected using optical landsat images and the lahar and pyroclastic flow zone simulated using the laharz program to detect areal extents of lahar and pyroclastic flows using landsat images supervised classification was performed after atmospheric correction by using a cosine of the solar zenith correction cost model as a result the extracted dimensions of pyroclastic flows are nearly identical to the calatrava volcanic province cvp monthly reports then areas of potential lahar and pyroclastic flow inundation based on flow volume using the laharz program were simulated and mapped finally the detected lahars and pyroclastic flow zones were compared with the simulated potential zones using laharz program and verified results showed satisfactory similarity 55 63 between the detected and simulated zone the simulated zones using the laharz program can be used as an essential volcanic hazard map for preventing life and property damages for merapi volcano and other hazardous volcanic areas also the laharz program can be used to map volcano hazards in other hazardous volcanic areas

textural and mineral chemistry constraints on evolution of merapi volcano indonesia abstract we analyze and compare the textures of merapi lavas basalts and basaltic andesites ranging in age from proto merapi through modern activity with the goal of gaining insights on the temporal evolution of merapi s magmatic system analysis of textural parameters such as phenocryst and microphenocryst crystallinity coupled with crystal size distribution theory provides information about the storage and transport of magmas we combine textural analyses with geochemical investigations for a comprehensive comparison of erupted lavas over time the chemical analyses identify crystal growth processes in magma chambers and underline differences between sample groups our work suggests the occurrence of two distinct histories presumably associated with at least two generally distinct types of rheological behaviors and storage transport systems these behaviors are associated with different plagioclase growth patterns with both groups influenced by late stage shallow decompression degassing induced microlite crystallization both groups contain amphibole crystals that indicate an early period of mid crustal to deep crustal storage of water rich magmas dome lavas from the 20th century eruptive activity indicate quasi steady state nucleation and growth evolution interspersed with episodes of reheating and textural coarsening suggesting residence in magma storage at multiple depths both 10 km and

textural and micro petrological variations in the eruptive products of the 2006 dome forming eruption of merapi volcano indonesia implications for sub surface processes the interplay between magma ascent degassing and changing magmatic properties are widely recognized as critical factors controlling the style of silicic volcanic eruptions microlite textures in samples from the prolonged dome forming eruption of merapi in 2006 provide a record of changing magmatic ascent conditions and shallow conduit processes throughout the eruption analysis of microlite textural parameters including measurements of areal number density na mean microlite size crystal aspect ratio and groundmass crystallinity combined with the monitoring record and field observations indicate that magma ascent paths change between continuous ascent at varying rates from a deeper magma storage region to ascent being temporarily stalled at shallow depths in the latter stages of the eruption supporting the idea of an ephemeral shallow magma storage region at merapi plagioclase microlite compositions show evidence of decompression induced degassing often displaying rims of anorthoclase and more k rich alkali feldspar sanidine anorthite contents also support the textural data of later erupted magma being temporarily stalled at shallow depths crystal size distributions csds are interpreted to show that both growth dominated and nucleation dominated crystallisation regimes existed during the 2006 eruption resulting from changing conditions of undercooling t during variable magma ascent paths by contrast microlite textural analysis and feldspar microlite compositions of samples from the fast growing lava dome of the second phase of the 2010 eruption prior to the cataclysmic events on 5 november indicate faster ascent rates a crystallisation regime more strongly dominated by nucleation due to high t and interaction of the 2010 magma with more hotter magma from depth

electromagnetic evidence for an ancient avalanche caldera rim on the south flank of mount merapi indonesia abstract long offset transient electromagnetic lotem data and vibrotem data from the south flank of mount merapi on java island indonesia are interpreted with one dimensional 1d inversions as well as two dimensional 2d forward modelling one dimensional joint inversions of several components of the electromagnetic field with occam s method reduce the number of equivalent models which were derived from inversions of single components and fit the data to a similar misfit the 1d results together with results from other geophysical measurements serve as the basic model for further 2d forward modelling the final model depicts a layering that follows the topography of the strato volcano in the depth range of 500 m to 1000 m the resistivity of the layers decreases rapidly downwards into a good conductor with resistivities below 10 m the deepest layer has a resistivity of 0 4 m which is quantitatively explained with a combination of saline fluids and hydrothermally altered minerals furthermore the final model supports a hypothesis from the interpretation of central loop tem transient electromagnetic data that there is a fault structure below the southern flank approximately 7 3 km south of the summit to the north of the fault the top of the good conductor is lowered from a depth of 500 m to 1000 m we propose that the fault structure coincides with an ancient avalanche caldera rim

velocity variations associated with the large 2010 eruption of merapi volcano java retrieved from seismic multiplets and ambient noise cross correlation we present a study of the seismic velocity variations that occurred in the structure before the large 2010 eruption of merapi volcano for the first time to our knowledge the technique of coda wave interferometry is applied to both families of similar events multiplets and to correlation functions of seismic noise about half of the seismic events recorded at the summit stations belong to one of the ten multiplets identified including 120 similar events that occurred in the last 20 hr preceding the eruption onset daily noise cross correlation functions ncf were calculated for the six pairs of short period stations available using the stretching method we estimate time series of apparent velocity variation avv for each multiplet and each pair of stations no significant velocity change is detected until september 2010 from 10 october to the beginning of the eruption on 26 october a complex pattern of avv is observed with amplitude of up to 1 5 per cent velocity decrease is first observed from families of deep events and then from shallow earthquakes in the same period avv with different signs and chronologies are estimated from ncf calculated for various station pairs the location in the horizontal plane of the velocity perturbations related with the avv obtained from ncf is estimated by using an approach based on the radiative transfer approximation although their spatial resolution is limited the resulting maps display velocity decrease in the upper part of the edifice in the period 12 25 october after the eruption onset the pattern of velocity perturbations is significantly modified with respect to the previous one we interpret these velocity variations in the framework of a scenario of magmatic intrusion that integrates most observations the perturbation of the stress field associated with the magma migration can induce both decrease and increase of the seismic velocity of rocks thus the detected avvs can be considered as precursors of volcanic eruptions in andesitic volcanoes without taking their sign into account

the geological evolution of merapi volcano central java indonesia merapi is an almost persistently active basalt to basaltic andesite volcanic complex in central java indonesia and often referred to as the type volcano for small volume pyroclastic flows generated by gravitational lava dome failures merapi type nuees ardentes stratigraphic field data published and new radiocarbon ages in conjunction with a new set of 40k 40ar and 40ar 39ar ages and whole rock geochemical data allow a reassessment of the geological and geochemical evolution of the volcanic complex an adapted version of the published geological map of merapi wirakusumah et al 1989 peta geologi gunungapi merapi jawa tengah geologic map of merapi volcano central java 1 50 000 is presented in which eight main volcano stratigraphic units are distinguished linked to three main evolutionary stages of the volcanic complex proto merapi old merapi and new merapi construction of the merapi volcanic complex began after 170 ka the two earliest proto merapi volcanic edifices gunung bibi 109 60 ka a small basaltic andesite volcanic structure on merapi s north east flank and gunung turgo and gunung plawangan 138 3 ka 135 3 ka two basaltic hills in the southern sector of the volcano predate the merapi cone sensu stricto old merapi started to grow at 30 ka building a stratovolcano of basaltic andesite lavas and intercalated pyroclastic rocks this older merapi edifice was destroyed by one or possibly several flank failures the latest of which occurred after 4 8 1 5 ka and marks the end of the old merapi stage the construction of the recent merapi cone new merapi began afterwards mostly basaltic andesite pyroclastic and epiclastic deposits of both old and new merapi 11 792 90 14c years bp cover the lower flanks of the edifice a shift from medium k to high k character of the eruptive products occurred at 1 900 14c years bp with all younger products having high k affinity the radiocarbon record points towards an almost continuous activity of merapi since this time with periods of high eruption frequency interrupted by shorter intervals of apparently lower eruption rates which is reflected in the geochemical composition of the eruptive products the holocene stratigraphic record reveals that fountain collapse pyroclastic flows are a common phenomenon at merapi the distribution and run out distances of these flows have frequently exceeded those of the classic merapi type nuees ardentes of the recent activity widespread pumiceous fallout deposits testify the occurrence of moderate to large subplinian eruptions vei 3 4 during the mid to late holocene vei 4 eruptions as identified in the stratigraphic record are an order of magnitude larger than any recorded historical eruption of merapi except for the 1872 ad and possibly the october november 2010 events both types of eruptive and volcanic phenomena require careful consideration in long term hazard assessment at merapi

effects of volatile behaviour on dome collapse and resultant pyroclastic surge dynamics gunung merapi 2010 eruption in 2010 gunung merapi central java indonesia generated two violent eruption sequences on 26 october and 5 november culminating in widespread pyroclastic density currents pdcs associated with the destruction of lava domes tephra from pdc deposits were analysed to examine pre dome collapse volatile behaviour and evidence of carbonate assimilation secondary ion mass spectroscopy sims depth profiles of plagioclase phenocrysts reveal that the 7 li 30 si ratios in 26 october products are higher in the glass compared to the crystal indicating a build up of li in the groundmass not observed in the 5 november samples higher li in the groundmass suggests gas accumulation and rapid development of conduit overpressure in the shallow plumbing system prior to the initial 26 october explosion which was only captured through the behaviour of quickly diffusing li and not h 2 o following the explosion induced decompression juvenile magma rapidly ascended in great volume to generate extremely destructive pdcs following subsequent dome collapses particularly on 5 november additionally 26 october tephras contain carbonate grains in the ash component and abundant co 2 within the lava lapilli groundmass glass which supports previous studies indicating assimilation of calc silicate lithologies by the merapi magma at depth in the plumbing system prior to the onset of 2010 activity

combination of a pressure source and block movement for ground deformation analysis at merapi volcano prior to the eruptions in 2006 and 2010 abstract we analyzed ground deformation prior to the eruptions in 2006 and 2010 at merapi volcano central java indonesia ground deformation was monitored by electronic distance measurement edm by measuring the slope distance toward 12 reflectors installed near the summit from five benchmarks on flanks every day a large change of slope distance csd was detected on the southeast and south baselines and a minor csd was detected on the north and northwest baselines during the pre eruptive stages of both the 2006 and 2010 eruptions we applied a block movement model to the south and southeast baselines and a spherical pressure source model to the csds on the north and northwest baselines using the finite element method fem the rates of block movement southward and the volume change of the pressure source increased on april 7 2006 and continued at constant rates until the appearance of a new lava dome on april 26 prior to the eruption in 2010 the block movement southeastward and the volume increase of the pressure source accelerated in the middle of october and acceleration continued until the first outburst on october 26 2010 temporal patterns of the block movement and the increase in the volume of the pressure source correlate well with the increase in seismicity of vt and mp earthquakes the pressure sources were obtained at a depth of 2 0 5 km below the summit and this position corresponds to the aseismic zone of vt earthquakes magma injection at the shallow part of this region causes an increase in the volume of the pressure source and inflation of the ground of the summit triggered gravitational slip southeastward or southward of the ground surface the volumes increases of the pressure sources were 9 7 1 m m 3 and 17 6 0 8 m m 3 in 2006 and 2010 respectively the volume increase is related to the scale and type of the eruption the effusive eruption in 2006 had a volcanic explosivity index vei of 2 and the explosive eruption in 2010 had a vei of 4 the directions and amounts of the block movement are strongly related to topography hydrothermally weak zone and underground gap near the summit between west and east domes

merapi central java indonesia an outline of the structural and magmatological evolution with a special emphasis to the major pyroclastic events abstract merapi volcano in the central part of java is regarded as the most active and most dangerous volcano in indonesia on the basis of field studies and geochronological data its history is divided into four periods ancient middle recent and modern merapi according to our preliminary age data the ancient period may have begun around 40 000 y bp and lasted until 14 000 y bp when the middle period begun the recent period begun around 2200 y bp and was replaced by the modern period after the eruption of 1786 during the middle merapi stage a mount st helens type edifice collapse occurred our data suggest that his event is younger than 6700 y bp and older than 2200 y bp during the recent merapi stage violent magmatic to phreatomagmatic eruptions twice interrupted the growth of the volcano the older gumuk phreatoplinian deposits cover the entire cone charcoal found within these deposits gave 14c ages of 2200 and 1470 y bp the overlying sambisari ash deposits were emplaced by violent pyroclastic surges directed towards the south i e to the present location of the town of yogyakarta they buried the shivaitic temple of sambisari at the start of the 15th century modern merapi is characterised by the persistent growth of a summit dome periodically interrupted by partial or total collapse of the dome to generate frequent merapi type nuees ardentes blocks and ash flows and associated surges or more exceptionally fall back st vincent type nuees ardentes scoria flows in contrast previous stages were characterised by effusion of long lava flows alternating with violent explosive phases generating essentially st vincent type nuees ardentes merapi lavas are calc alkaline with a compositional range between 49 5 and 60 5 wt sio2 moreover high k basaltic andesites represent about 90 of merapi lavas disequilibrium features are common in the mineralogical assemblage plagioclase orthopyroxene clinopyroxene olivine amphibole titanomagnetite scarce alkali feldspar macroscopic and microscopic textural heterogeneities are related to magma mixing that may have buffered the compositions of lavas and caused the restricted range of compositions our studies of past activity at merapi provide some insights into future activity and to related volcanic hazards it is clear that merapi has the potential of eruptions much more powerful than observed during the historic period

merapi volcano java indonesia and merapi type nuee ardente a particular nuee ardente type merapi type avalanche nuee has been defined at the merapi volcano because of its prominent role in the recent activity of the volcano gravity plays a significant role during the eruption

prospects and pitfalls in integrating volcanology and archaeology a review abstract volcanic eruptions and interactions with the landforms and products these yield are a constant feature of human life in many parts of the world seen over long timespans human volcano interactions become stratified in sedimentary archives containing eruptive products and archaeological remains this review is concerned with charting the overlapping territory of volcanology and archaeology and attempts to plot productive routes for further conjoined research we define archaeological volcanology as a field of study that brings together incentives insights and methods from both volcanology and from archaeology in an effort to better understand both past volcanism as well as past cultural change and to improve risk management practices as well as the contemporary engagement with volcanism and its products there is an increasing appreciation that understanding these human impacts and manifold human volcano interactions requires robust multi inter or even trans disciplinary collaboration our review is written in the hope of providing a clearinghouse resource that i maps the many forms of past human volcano interactions ii provides study design templates for how to integrate archaeological perspectives into investigations of past volcanism and iii makes suggestions for how the insights gained from such an archaeological volcanology can be integrated into reducing contemporary and future vulnerability amongst at risk communities

modeling the density at merapi volcano area indonesia via the inverse gravimetric problem 1 merapi is a high risk andesitic volcano in central java indonesia very little information is known about the detailed regional density structure around merapi and its neighbor volcano merbabu we compute a subsurface three dimensional 3 d model of anomalous density for the volcanoes merapi and merbabu in central java indonesia by inversion of the gravity field as input for the inversion methodology gravity observations from 443 points whose 3 d coordinates are determined by gps are used the inversion algorithm is based on an explorative approach to fit a least squares condition including a balancing factor between the minimization of the residuals and the anomalous mass a mean density about 2242 kg m3 for the region of merapi and merbabu has been computed by least squares adjustment results of the inversion show major low density contrasts up to 242 kg m3 and positive structures about 264 kg m3 referred to the determined mean density a density anomaly relative high with densities up to 264 kg m3 is connecting the volcanoes in a 152 course from nw to se and might be built of older basaltic lava low density contrasts about 242 kg m could be found in agreement with magnetotelluric and electromagnetic results generally the identified high and low density bodies are in agreement with the results of other geophysical methods such as electromagnetic and magnetotelluric prospecting or geological formations and structures a porosity about 21 is derived for the largest negative density bodies about 242 kg m3 furthermore the density model gives some new information about the controversial origin of a hill formation near merapi and is also used to discuss the possible existence of a shallow magma chamber which is also a controversial subject generally the density model serves as basic information for the interpretation of geodetic and geophysical observations and confirms existing results from magnetotellurics electromagnetics and seismic data interpretation

pedosedimentary and climatic reconstruction of the last interglacial and early glacial loess paleosol sequence in south tadzhikistan abstract the thick loess paleosol sequences in tadzhikistan which indirectly record the environmental changes from the upper pliocene to the present day have been extensively described from a chronostratigraphical and archaeological point of view the genesis of the soil sedimentary complexes and their implications for palaeoenvironmental reconstruction in tadzhikistan however have been considered only relatively recently bronger a winter r derevjanko o aldag s 1993 loess paleosol sequences in tadjikistan as a palaeoclimatic record of the quaternary in central asia quaternary proceedings 4 69 81 lomov s p tursina t v zhou l p 1996 magnetic susceptibility of soils micromorphology and possible reconstructions of climate in soil micromorphology studies in soil diversity diagnostics dynamics 10th international working meeting on soil micromorphology moscow russia july 8 13 1996 p 145 the pedocomplex of last interglacial and early glacial age oxygen isotope stage 5 in the tagidjar and darai kalon sections near the town of khovaling is represented by three major stages of soil formation the soil characteristics have been micromorphologically analysed the distinction between primary and secondary carbonates is of major importance to understand the soil forming processes the relative distribution of needle fibre calcite nfc micritic infillings m hypocoatings chc coarse calcitic grains ccg and calcified root cells crc provides detailed insights into the environmental conditions prior during and following pedogenesis the abundance of coprolitic aggregates ca and pupal chambers gives a clear indication of the rate of biological activity which prevailed during the last two soil forming stages void pseudomorphs after gypsum crystals gypsum pseudomorphs are frequently observed beneath the cca horizons of the paleosols using the present day climate and soilscape as a reference base the obtained pedosedimentary events detected in the tadzhikistan sections provide a detailed palaeoenvironmental record indeed glacial and interglacial climates and soils respond to contemporaneous climatic schemes and soil forming processes which are still active in the region today the amount and the seasonal variability of precipitation mostly are at the origin of the variable soils formed during glacial and interglacial ages

textural history of recent basaltic andesites and plutonic inclusions from merapi volcano mt merapi in central java is one of the most active stratovolcanoes on earth and is underlain by a multistage plumbing system crystal size distribution analyses csd were carried out on recent merapi basaltic andesites and co eruptive magmatic and plutonic inclusions to characterise the crystallisation processes that operate during storage and ascent and to obtain information on respective time scales the basaltic andesites exhibit log linear kinked upwards csd curves for plagioclase and clinopyroxene that can be separated into two main textural populations large plagioclase phenocrysts 1 6 mm make up one population but correspond to crystals with variable geochemical composition and reflect a period of crystal growth at deep to mid crustal levels this population was subsequently influenced by crystal accumulation and the onset of crustal assimilation including the incorporation of high ca skarn derived xenocrysts textural re equilibration is required for these crystals to form a single population in csd a second episode of crystal growth at shallower levels is represented by chemically homogenous plagioclase crystals 1 6 mm in size crustal assimilation is indicated by for example oxygen isotopes and based on the csd data crystallisation combined with contamination is likely semi continuous in these upper crustal storage chambers the csd data observed in the basaltic andesite samples are remarkably consistent and require a large volume steady state magmatic system beneath merapi in which late textural equilibration plays a significant role plagioclase csds of co eruptive magmatic and plutonic inclusions may contain a third crystal population 1 mm not found in the lavas this third population has probably formed from enhanced degassing of portions of basaltic andesite magma at shallow crustal levels which resulted in increased crystallinity and basaltic andesite mush inclusions a suite of coarse plutonic inclusions is also present that reflects crystallisation and accumulation of crystals in the deep merapi plumbing system as deduced from csd patterns and mineral assemblages

14c ages and activity for the past 50 ka at volcan galeras colombia abstract volcan galeras is the southernmost colombian volcano with well recorded historic activity the volcano is part of a large and complex volcanic center upon which 400 000 people live historic activity has centered on a small volume cone inside the youngest of several large amphitheaters that breach the west flank of the volcano away from the city of pasto population 300 000 lava flows sio2 between 54 6 and 64 7 wt have dominated activity for more than 1 ma but explosive events have also occurred joint studies by volcanologists from colombia ecuador peru bolivia argentina and the united states produced 24 new14c ages and more than 100 stratigraphic sections to interpret the past 50 ka of activity at galeras including sector collapse events the youngest collapse event truncated 12 8 ka lava flows and may have occurred as recently as 8 to 10 ka tephra fall material rapidly thins and becomes finer away from the vent area the only widespread marker in the

a detailed tephrostratigraphic framework at merapi volcano central java indonesia implications for eruption predictions and hazard assessment abstract the upper part of merapi volcano is characterised by a summit crater breached to the southwest and occupied by an unstable lava dome episodes of dome growth have usually resulted in partial dome collapse events that have generated pyroclastic flows in recent years these have inundated the southwestern lower flanks and in the past other sectors of the volcano have been affected this recent pattern of volcanic activity since the 1880s is well known from direct observations in this study the eruptive record extending back to mid holocene times is deduced from the stratigraphy and chronology of volcaniclastic deposits this record forms an important basis from which the average periodicity of eruptions at merapi and the severity and the extent of future eruptions can be assessed the most complete record of eruptive activity from merapi volcano is found in the deeply dissected volcaniclastic fans of the lower flanks here successions of numerous coarse ash and lapilli beds are interbedded with andic soil material thin pyroclastic flow and surge deposits and a hitherto unrecognised inter regional tephra marker bed many of these tephra beds can be reliably correlated around the flanks of merapi volcano and can be distinguished on the basis of physical appearance and stratigraphic association these formations can be reliably used to correlate units around the flanks of the volcano in the deeper parts of this stratigraphic succession pyroclastic products originating from the adjacent merbabu volcano are also recognised and provide evidence of concurrent activity at both volcanoes it is clear from the stratigraphic record that relatively large magnitude eruptive volume to 3 7 108 m3 eruptions have been generated at merapi volcano these eruptive deposits are typically produced from pyroclastic flow and or pyroclastic fall events most of the fall beds are characterised by single to multiple upward fining pumiceous or scoriaeous units sometimes overlain by ash cloud surge beds isopach maps have been produced for several of these tephra beds and most of them show either west southwest south and southeast dispersion except for the ngrangkah tephra which shows no systematic direction or distribution sub plinian or plinian to vulcanian open vent styles of activity appear to have been common at merapi volcano such eruptive episodes are in contrast with the style of activity that had been occurring at merapi volcano in the last two centuries clearly the range of eruptive events likely to be experienced at merapi volcano needs to be more critically considered in any existing or future hazard assessment and contingency planning programme

multi scale topographic analysis of merbabu and merapi volcanoes using wavelet decomposition with the increasing availability of data geo sciences have experienced deep changes in handling and processing it one of the presently explored research directions concerns the systematic decomposition and understanding of topographical features without the subjective interactions of humans this can eventually lead to fully automated algorithms for topographic analysis and understanding this paper aims at being a contribution to this broad research area for the specific cases of stratovolcanoes whose general geometry are very similar to a perfect cone more specifically this paper addresses two issues 1 is it possible to separate erosion features local variations from structural features large variations on stratovolcanoes through mathematical expression 2 can information on volcanic activity intensity age etc be retrieved from a topographic analysis the study has been conducted from two volcanoes in central java indonesia the merapi and the merbabu the dem of these volcanoes has been sampled using concentric circles with a radius ranging from 500 to 5 000 m horizontal distance to the summit the data conversion and sampling was performed in arcmap while the data analysis was carried out with matlab using discrete meyer wavelet decomposition results provide an insight on large scale topographic variations long wave wavelet that have been separated from rapidly varying topographic features such as lahar channels short wave wavelets observations proved that flanks where the most recent volcanic activity occur like at merapi volcano on the s se flank present a very low variability of long wave variations whereas short wave variations are important the author argues that this feature is due to highly erosive lahars that dig the valleys combined with a recent production of material and volcanic growth keeping the overall structure regular flanks with lesser activity are characterized at the two volcanoes by important long wave variations most certainly due to long term differential erosion and different level of short waves variations comparing the two volcanoes results show that the valleys of merapi and merbabu volcanoes are deeply incised indicating recent periods of high activity with reworkable material eroded by lahars and other channels deepening processes the topography of the summit area of merapi volcano is smoother than at merbabu volcano where deep erosion features extend up to the summit area this difference is most certainly due by the material production at the summit of merapi volcano developing such classification is important for automated mapping and computer recognition of volcanic past activities and their impacts on landscapes it is the based for the development of decision trees that assist computer assisted and automated computer vision

self potential and ground temperature at merapi volcano prior to its crisis in the rainy season of 2000 2001 abstract rainwater infiltration into the active lava dome of merapi volcano central java has often been suggested as a triggering mechanism for partial dome collapse and subsequent eruptive behavior however the phenomenon has not been systematically investigated we use a multi parametric approach to study the interaction of the hydrologic and magmatic system near the lava dome prior to its crisis in early 2001 we describe the hardware concept for a continuous monitoring system for self potentials u sp and ground temperature t installed in august 2000 at the solfatara woro only 150 m from the active lava dome relating the data from this station to measurements of rainfall air pressure solfatara temperature and seismicity several effects can be distinguished a a long term correlation is observed between electrode temperature difference and sp with estimated coupling coefficients of 2 1 0 5 mv c b after individual rainfall events u t signatures show a typical pattern of positive charge accumulation at the hot electrodes near the fumarolic vents c an exceptional anti correlation between u and t is observed in january 2001 during a period of rapid dome growth prior to the collapse and eruptive crisis d wavelet analysis of sp reveals the sporadic occurrence of periodic fluctuations with a clear 12 h s2 component because of their amplitude of up to 100 mv km and their periodicity s2 but not 24 h or lunar 12 h 25 min these fluctuations are unlikely to be caused by natural magnetic field variation or by earth tides instead they do seem correlated but not in phase with atmospheric pressure changes we discuss effects a d in the framework of source mechanisms related to water lava interactions

the pre eruption conditions for explosive eruptions at merapi volcano as revealed by crystal texture and mineralogy abstract we analyze the textures and mineralogy of merapi tephra generated during explosive vei 3 4 eruptions over the past 2000 years and compare these data with those observed for merapi dome and flow lavas we find that the merapi pumiceous tephra and lava textures differ significantly with respect to small size crystal populations but that phenocryst textures are generally similar a similar initial phase of crystallization is indicated for tephras and lavas in mid crustal 10 km depth reservoirs subsequent textural differences are mainly affected by ascent rate and degassing during ascent and for dome lavas with temporary storage in shallower reservoirs these differences also correspond to different eruptive styles our analyses include study of pumices lava and breadcrust bomb samples including samples from some of the most recent explosive episodes prior to the 2010 eruption textural analyses of youthful breadcrust bomb samples yield insights on one type of transition between effusive and explosive eruptive styles involving pressure build up under a degassed crystalline shallow conduit plug in general comparison of the crystal size distributions and calculated residence times among the effusive and explosive eruptive styles suggests that the two main magma product types resided for similar lengths of time in a mid crustal reservoir before ascending toward the surface and either erupting explosively tephra or stagnating in a shallow magma chamber prior to extrusion lava the interpretation is supported by the occurrences of amphibole in pristine condition in tephra and in altered state in lava finally the 1872 and 2010 explosive eruptions are examined and compared with others over the past three millennia the 2010 bulk rock compositions overlap with products of other major explosive merapi eruptions such as the ngrangkah tegalsruni temusari and kepuharjo tephras the 2010 products show a gradational late stage mafic enrichment dissimilar to 1872 which showed little

unravelling a complex volcanic history from fine grained intricate holocene ash sequences at the tongariro volcanic centre new zealand abstract holocene volcanism at the tongariro volcanic centre tgvc at the south western end of the taupo volcanic zone tvz new zealand involved eruptions from at least three centres and was dominated by numerous small eruptions of vei 1 4 these produced very thin grey to black fine to coarse ash deposits of basaltic andesite to andesitic composition being unable to uniquely recognise and correlate these deposits presented a challenge in documenting the complete eruption record from the tgvc and to distinguish the periods of activity associated with each centre previous studies combined fine and poorly distinguishable tephras into mappable formations comprising many tens of units bracketed by rhyolitic marker tephras derived from the tvz caldera centres to the north very fine scaled mapping and analysis of glass of holocene tephras in the tgvc were used to document the comprehensive explosive eruption record over the last 12 000 cal years glass compositional analyses distinguished the tephras from the three main centres of the tgvc mt ruapehu mt ngauruhoe and red crater the latter two being part of the mt tongariro complex the three vents are sufficiently distinctive to be defined by ratios of major element oxides in the glasses with the oxide pair k 2 o feo being the most diagnostic ruapehu sourced tephras are generally higher in k 2 o 1 4 4 wt and lower in feo 3 7 8 3 wt than tongariro derived units red crater and ngauruhoe the diagnostic analyses provided the basis for correlating multiple tephra packages on the ring plains surrounding the tgvc and for establishing a revised eruption frequency for each of the volcanoes the new data show that ngauruhoe began erupting about 7000 cal years ago up to 4500 cal years earlier than previously thought

loess chronology of the middle and upper pleistocene in tadjikistan the loess paleosol sequences of central asia are continuous terrestrial records of the quaternary period and enable detailed comparison with paleoclimatic archives such as marine and ice core records in order to reconstruct regional and global paleoclimatic and paleoecological development during the past 130 000 years thermoluminescence tl and infrared stimulated luminescence irsl dating methods are applied to the extensively studied loess paleosol sequence of the section at darai kalon chashmanigar tadjikistan in order to determine a more accurate chronological framework and climatostratigraphic reconstruction for the last interglacial glacial cycle luminescence dating suggests that the loess above the first pedocomplex from the top pc1 accumulated during the last glacial period a high accumulation rate of up to 1 20 m per 1000 years was determined for the last glacial loess especially for the uppermost 5 8 m pc1 formed during the last interglacial period oxygen isotope stage 5 the loess between pc1 and pc2 is designated to be of penultimate glacial deposition age infrared stimulated luminescence and tl age estimates are in agreement to 80 000 years before present bp indicating a long distance transport of the aeolian dust prior to deposition the upper numerical age limit range is between 300 000 and 450 000 years however reliable dating of the loess older than 130 000 years is not possible due to age scatter between samples and an inadequate increase of paleodose with depth this high resolution dating study underlines the importance of the section at darai kalon and indicates that it is one of the most continuous loess paleosol records of the northern hemisphere the chronological results are particularly important for the reconstruction of the human evolution in central asia suggesting much older age estimates than previously obtained for most of the archeological key sites associated with pc5 and pc4 in tadjikistan