instantaneous end moraine and sediment wedge formation during the 1890 glacier surge of bruarjokull iceland abstract contemporary understanding of the behaviour of surging glaciers and ice streams is hampered by the lack of data on landsystem evolution and sedimentary environments this study concerns the ice marginal environment of the surge type bruarjokull in iceland the sediment distribution in the glacier forefield as well as the morphology sedimentology and tectonic architecture of the 1890 end moraine is investigated for highlighting the interaction between very dynamic ice and sediment landform associations as a result of substrate bedrock decoupling during the 1890 surge subglacial sediment was dislocated across the bedrock surface and deformed compressively leading to gradual substrate thickening and the formation of a sediment wedge in the marginal zone a drop in subglacial porewater pressure at the very end of the surge led to substrate bedrock coupling and a stress transfer up into the sediment sequence causing brittle deformation of the substrate simultaneously the glacier toe ploughed into the topmost part of the marginal sediment wedge initiating the moraine ridge construction fine grained and incompetent sediment deformed in ductile manner resulting in a narrow moraine dominated by rooted folds while coarse grained and competent sediment deformed in brittle fashion resulting in a wider moraine dominated by thrust blocks a new sequential model of subglacial and ice marginal processes operating during a glacier surge is proposed illustrating the stepwise formation of a marginal sediment wedge and an end moraine a twofold inseparable marginal end product that formed during the last days of the 1890 surge

impact of volcanic processes on the cryospheric system of the peteroa volcano andes of southern mendoza argentina abstract soil temperatures of the active volcanic complex peteroa situated in the cordillera principal between chile and argentina at 35 15 s and 70 35 w approximately were monitored in the area and local geomorphology periglacial geomorphology presence of permafrost and cryoforms was studied the present contribution also resulted in a comparison of two consecutive analyses of the volcano peak carried out with special thermocameras agema tvh 550 fur p660 in order to study the thermal range of different hot and cold sites selected in 2009 the thermocameras were used ascending by foot and also during flights with a cessna 180 a night expedition to the volcanic avalanche caldera at up to 3900 m asl approximately completed the monitoring activity of 2010 hot zones were associated to present volcanism and cold zones to the presence of glacier ice and shadowy slopes with possible presence of permafrost identifying and mapping uncovered and covered ice was possible with the help of monitoring and geomorphological interpretation related to the upper englacement which is severely affected by volcanism glaciers are retreating toward the north or approaching the rims of the volcanic avalanche caldera leaving islands of ice associated with superficial permafrost the cryogenic area with slope permafrost was identified through active protalus and sedimentary cryogenic slopes craters have undergone considerable thermal changes in comparison to the year 2009 and new much more vigorous fumaroles have appeared in hot areas detected in 2009 following a tendency toward the west new subaquatic heat columns that appeared in crater 3 crater walls and glaciated areas vanished supplying cold water and thus contributing to the formation of a new lake in crater 4 a possible post seismic shift of the volcanic activity may provide geodynamical evidence of the changes registered in other areas after the earthquake of 27 february 2010

volcano ice interactions precursory to the 2009 eruption of redoubt volcano alaska abstract in late summer of 2008 after nearly 20 years of quiescence redoubt volcano began to show signs of abnormal heat flow in its summit crater in the months that followed the excess heat triggered melting and ablation of redoubt s glaciers beginning at the summit and propagating to lower elevations as the unrest accelerated a variety of morphological changes were observed including the creation of ice cauldrons areas of wide spread subsidence punctures in the ice carved out by steam and deposition from debris flows in this paper we use visual observations satellite data and a high resolution digital elevation model of the volcanic edifice to calculate ice loss at redoubt as a function of time our aim is to establish from this time series a proxy for heat flow that can be compared to other data sets collected along the same time interval our study area consists of the drift glacier which flows from the summit crater down the volcano s north slope and makes up about one quarter of redoubt s total ice volume of 4 km 3 the upper part of the drift glacier covers the area of recent volcanism making this part of ice mass most susceptible to the effect of volcanic heating moreover melt water and other flows are channeled down the drift glacier drainage by topography leaving the remainder of redoubt s ice mantle relatively unaffected the rate of ice loss averaged around 0 1 m 3 s over the last four months of 2008 accelerated to over twenty times this value by february 2009 and peaked at greater than 22 m 3 s just prior to the first major explosion on march 22 2009 we estimate a cumulative ice loss over this period of about 35 million cubic meters m m 3

progradation of the late quaternary gediz delta turkey abstract detailed 3 5 khz seismic reflection profiling and coring have shown that the continental shelf break and slope off izmir bay turkey are formed by prograding deltaic silty mud sequences the muds contain shallow brackish water benthic and cold water planktonic foraminifera they were deposited when sea level was about 110 m below its present position during the last pleistocene glaciation slumping took place on the prodelta slope leaving rotational slump scars and imbricate slump blocks downslope delta top truncation took place in shallow water by erosive coastline retreat after distributary abandonment there has been little or no sedimentation since that time outer izmir bay is thus floored by relict sands following rapid post glacial transgression the gediz delta was reestablished in izmir bay archaeological evidence shows it has prograded during the last 3000 yrs at least six shifts in the position of the gediz mouth are distinguished during this time and abandoned delta top channels can be correlated with submarine delta lobe sequences

shallow magma transport for the 2002 3 mt etna eruption inferred from thermal infrared surveys abstract the 26 october 2002 28 january 2003 eruption of mt etna volcano was characterised by lava effusion and by an uncommon explosivity along a 1 km long eruptive fissure on the southern upper flank of the volcano the intense activity promoted rapid growth of cinder cones and several effusive vents analysis of thermal images recorded throughout the eruption allowed investigation of the distribution of vents along the eruptive fissure and of the nature of explosive activity the spatial and temporal distribution of active vents revealed phases of dike intrusion expansion geometric stabilization and drainage these phases were characterised by different styles of explosive activity with a gradual transition from fire fountaining through transitional phases to mild strombolian activity and ending with non explosive lava effusion here we interpret the mechanisms of the dike emplacement and the eruptive dynamics according to changes in the eruptive style vent morphology and apparent temperature variations at vents detected through thermal imaging this is the first time that dike emplacement and eruptive activity have been tracked using a handheld thermal camera and we believe that its use was crucial to gain a detailed understanding of the eruptive event

quaternary deposits of the buyuk menderes graben in western anatolia turkey implications for river capture and the longest holocene estuary in the aegean sea abstract the buyuk menderes graben is a seismically active depositional basin in the n s extensional tectonic region of western anatolia turkey it extends in an e w direction and is bounded by the aegean sea to the west the infill of this tectonic basin comprises ca 850 m and 245 m thick clastic sequences of neogene and quaternary respectively and the quaternary part of the basin fill is presented here by the help of seismic sections and boreholes results show that the studied succession was made of unconsolidated mostly fine grained clastic sediments of marine and continental sequences interfingered with each other the marine counterpart forms three relatively short approx 30 km and one long approx 100 km from modern coastline sediment wedges representing sea transgressions onto the graben the last one was a rapid incursion that occurred in the middle holocene forming the longest estuary of the aegean sea in western anatolia the filling of this estuary caused the decline of some historical harbours and settlements in the region while marine based events occurred in the west of the graben alluvial and fluvial processes produced marginal and axial deposits in the east of graben respectively in general the continental succession of quaternary is thinner than its marine equivalent probably due to sea level fluctuations in addition the sedimentation rate increased suddenly during deposition of the last marine sequence estuarine deposits in the holocene it is likely that this was the result of enlargement of the drainage area of the river buyuk menderes due to a river capture that occurred in the latest stages of pleistocene

birth growth and morphologic evolution of the laghetto cinder cone during the 2001 etna eruption we have undertaken detailed observations of the formation of the laghetto cinder cone a new cone that formed during a 2 week period of intense activity in piano del lago on the upper slopes of mount etna in summer 2001 we describe the events leading to the formation of a small graben the formation of pit craters on the base of the graben the onset of phreatomagmatic activity a transition to intense strombolian activity and a return to phreatomagmatic activity as the eruption came to an end we discuss the reasons for these transitions and describe the morphological development of the cone during these events arcuate cracks on the southern part of the cone were related to withdrawal of magma at the end of the eruption other slope instabilities that developed during the eruption include the formation of small radial grain flows on the outer flanks of the cone and the collapse into the crater of part of the crater rim some of the failure planes we observed were first identified using a flir tm 695 thermal infrared camera this is the first time that infrared thermography has been used to detect instability of volcanic structures results obtained during this test case demonstrate that thermal cameras are a very useful tool for studies of volcanic instability

plio quaternary seismic stratigraphy and depositional history of the ulleung basin east sea association with debris flow activity abstract we analyzed multi channel seismic reflection profiles to decipher the plio quaternary stratigraphic architecture and resolve the depositional history of the ulleung basin a detailed seismic stratigraphic interpretation revealed nine seismic units units 1 9 separated by unit boundaries in the plio quaternary deposits of the ulleung basin unit 1 pliocene is dominated by debris flow deposits dfds throughout the basin units 2 9 quaternary are characterized by stacked dfds interbedded with thin hemipelagic sediments along the southern slope whereas the northern basin floor is filled with hemipelagic and pelagic sediments the areal distribution and dimensional characteristics of the dfds indicate that sedimentation in the ulleung basin has been controlled by a combination of tectonic movement eustatic changes in sea level and gas hydrates dissolution and dissociation during the pliocene unit 1 sedimentation was mainly controlled by tectonic movements causing margin wide slope failures under the compressional regime large sediment deposits were supplied to the basin through mass transport processes resulting in an abundance of dfds throughout the basin during the quaternary units 2 9 compressive stress decreased sharply causing the dfds to retreat landward at that time sedimentation was mainly influenced by eustatic changes in sea level and gas hydrates dissolution and dissociation as the sea fell to the lowstand slope failures were activated by the generation of high pore water overpressure and the generation of weak layers in the sediments resulting in stacked dfds however as the sea level rose to the highstand sediment was primarily deposited via hemipelagic and pelagic processes due to increased hydrostatic pressure and slope stability

geoarchaeological evidence for dredging in tyre s ancient harbour levant abstract chrono stratigraphic data from tyre s ancient northern harbour delineate extensive dredging practices during the greco roman and byzantine periods radiocarbon dates from four cores consistently cluster between ca 500 b c and 1000 a d and indicate rapid rates of sedimentation in the basin namely 10 mm yr during the greco roman and byzantine periods compared to 0 5 1 mm yr for the period 6000 4000 b c absence of strata between 4000 b c and 500 b c is not consistent with a natural base level sediment sink and cannot be interpreted as a depositional hiatus in the high stand systems tract ancient dredging is further corroborated by persistent age depth inversions within the fine grained harbour facies these data support removal of middle bronze age to persian period sediment strata with deliberate overdeepening of the harbour bottom by greco roman and byzantine societies

architecture and structural evolution of an early little ice age terminal moraine at the surge type glacier mulajokull iceland the internal architecture and structural evolution of the arnarfellsmular terminal moraine at mulajokull a surge type glacier in central iceland is described in order to demonstrate submarginal and proglacial glaciotectonic processes during glacier surging as well as constraining the age of the maximum extent of the glacier the moraine is 4 7m high 50 100m wide and composed of a highly deformed sequence of loess peat and tephra that is draped by till up to the crest the internal architecture is dominated by steep high amplitude overturned folds and thrusts in the crest zone but open low amplitude folds on the distal slope section balancing suggests a basal detachment decollement depth of 1 4m and a total horizontal shortening of around 59 this implies that the glacier coupled to the foreland about 70m up glacier from its terminal position to initiate the formation of the moraine the structural evolution is polyphase in that the formation commenced with low amplitude open folding of the foreland followed by overfolding and piggyback thrusting radiocarbon dating and analysis of tephra layers along with historical references indicate that the most likely time of moraine formation was between a d 1717 and 1760 which suggests that mulajokull had its little ice age maximum and most extensive surge earlier than many other surge type glaciers in iceland

analyses of fault mechanisms and expansion of southwestern anatolia since the late miocene abstract neotectonic field studies and detailed analyses of neogene and quaternary fault mechanisms in southwestern anatolia enable us to recognize a succession of compressional and extensional events and to characterize the direction of corresponding regional stresses the three most important compressive phases occurred during the miocene and a much smaller one near the plio quaternary boundary the last one or two interrupted a widespread extension of much greater duration and amplitude the whole tectonic evolution resembles that of the aegean the large extension by normal faulting is consistent with a minimum stress along a nne ssw average direction it appears that this direction was n s during the pliocene and changed to ne sw sometime during the quaternary this dominant nne ssw extension which began during late miocene or earliest pliocene was related to the development of the southwestern anatolian graben system

global distribution of koppen geiger climate types during the last glacial maximum mid holocene and present abstract this research presents koppen geiger k g climate type maps of the last glacial maximum lgm of 21 000 years ago 21 ka the mid holocene mh of 6 ka and the present 1976 2005 data used to calculate and map the k g climate type are year monthly mean 2 m air temperature and precipitation from the national center for atmospheric research ncar community climate system model version 4 ccsm4 community atmosphere model version 4 cam4 as part of the coupled model intercomparison project phase 5 cmip5 results suggest that the model depicts similar modern climate distributions as in data based research excepting a larger distribution of tropical wet dry and humid subtropical types and a smaller distribution of hot arid and hot semi arid types the modeled modern k g climate types cover similar percentages of earth s terrestrial and marine surface as during the mh with slight enlargement of the tropical wet dry and decreased area of mesothermal monsoonal hot summer type in the modern period at the lgm the k g polar e climate was far more extensive than in modern times with concurrent decreases in area of the tropical a climates because koppen type classifications are intended to mimic the biome distributions these results may be helpful in identifying biotic realms from the geologic past and the potential vegetative response to future climate changes

foraminifera as markers of holocene sea level fluctuations and water depths of ancient harbours a case study from the bay of elaia w turkey abstract the absence of common sea level indicators in the study area of elaia pergamum s harbour city in hellenistic and roman times forced to establish a new reliable indicator which was found in the foraminifera associations in connection with the transgressive contact the strength of this indicator is the exclusion of post depositional compaction accompanied by a well dated archaeological index point at a breakwater the micropalaeontological indicator enabled the establishment of a reliable regional sea level curve rsl curve for the bay of elaia it is in good agreement with other curves for the aegean region and in general agreement to the glacio hydro isostatic model for the region our sea level curve proves for the first time at a continental site on the turkish aegean coast the today s sea level peak water depth modelling for the so called closed harbour of elaia reveals the capacity to fully accommodate the common ship classes of hellenistic and early roman times until around 150 ce while water depth estimates for the so called open harbour of the city verifies the usage of the adjacent ship sheds during elaia s prime

stratigraphy of late holocene deposits of the ancient harbour of marseilles southern france the late holocene stratigraphy of marseilles harbour is presented together with archaeological evi dence and radiocarbon data an anthropogenic oyster midden dated between c 4260 and 3400 14 c yr bp is followed by a period of siltation that ended the accretionary growth of an algal marl deposit this event was caused by early human settlement subsequently the coastline was subject to progradation it is argued here that the development of the e rst town of marseilles c 2600 years ago accelerated soil erosion and sediment deposition in the harbour area

the morphology structural evolution and significance of push moraines abstract push moraines glaciotectonic ice marginal moraines have a restricted distribution at modern glacier margins and consequently are of potential value in reconstructing pleistocene ice sheets providing data both on former glaciodynamics and on the palaeoenvironment of the glacial foreland to the wider earth science community push moraines are of interest as analogues for thin skin tectonics within orogenic belts this paper reviews the morphology structural geology formation and significance of push moraines the morphological and structural characteristics of small seasonal push moraines through to large multi crested examples produced by sustained glacier advances are reported before the primary controls on push moraine formation are examined these controls include the nature of the applied glacial stress field the presence and properties of decollement horizons and the shear strength and rheology of the glacial foreland a conceptual model of push moraine formation is introduced in which the range of observed morphological and structural forms are viewed within a matrix defined by the main variables which control their formation the absence of consensus over which of these variables is of greatest importance currently limits the significance of push moraines in palaeoglaciological research as a consequence this review emphasises the need for future research in order to realise the true potential of push moraine in the reconstruction of pleistocene environments

human influence and the changing geomorphology of mediterranean deltas and coasts over the last 6000 years from progradation to destruction phase the present geomorphology of the mediterranean s coasts is largely a product of an intricate long term relationship between nature and human societies a cradle of ancient civilisations the mediterranean has seen its shores occupied by humans since prehistory and is therefore a particularly pertinent unit of analysis the morphotectonic context and other forcing agents e g climate shaped out a highly diversified coastal morphology and generated a sediment supply regime potentially favourable to the formation of numerous open coast deltas and bay head deltas in infilled rias as sea level stabilised during the mid holocene this supply of riverine sediment has also been the key agent in mediating human occupation of the mediterranean s clastic coasts expressions of this relationship have been extensively archived in clastic coastal deposits including base level deltaic and estuarine sedimentary sinks which comprise records to explore the interactions between geosystems and the human environment the stratigraphic sequences in these coastal sedimentary archives comprise in many places a clearly identified anthropogenic signature notably in ancient harbours some of which underwent extremely rapid silting up due to massive sediment sourcing generated by new agricultural practices from the neolithic onwards increasing human influence especially over the last 3000 years has been in turn an important driver of changes in sediment supply strongly modulating deltaic development pulses of sediment supply from catchments rendered vulnerable by human perturbations during the roman period resulted in a new cycle of inception of many other deltas and in rapid delta growth e g the ebro the po the arno and the ombrone another progradation dynamic during the little ice age at a time of strong rural population growth river discharge increases technological developments and urbanisation further consolidated delta growth understanding the life cycle of these deltas since their initial formation is in turn key to unravelling the relative role of natural and anthropogenic forcing agents rapid climate changes are deemed to have contributed through both the stripping of landscapes rendered fragile by human activities and active fluvial sediment transport to the coast but disentangling climate change effects from human impacts in the mediterranean remains a challenge the patterns of subsequent deltaic growth and delta morphodynamics reflect adaptations to pulsed sediment supply river discharge variations the microtidal fetch limited context of the mediterranean and direct engineering interventions the progradation dynamic of the roman period and little ice age contrasts markedly with the situation of common coastal destabilisation over the last two centuries particularly well documented for the last 50 years this period has been characterised by reduced sediment flux to base level geosystems due to catchment reforestation retenion within reservoirs fluvial regulation and dredging resulting in the erosion of deltas and barrier lagoon and beach dune systems large stretches of shoreline and narrow coastal plains have been massively engineered for coastal defence and protection against erosion but also for the construction of marinas leisure harbours and artificial beaches resulting in the emergence of veritable artificial seafronts these interventions have collectively and progressively raised societies to a pervasive and overarching position in the geomorphic stability instability of the mediterranean s coasts a situation that will be exacerbated by pressures from sea level rise paving the way for rampant coastal erosion and delta destruction

sedimentary and structural evolution of a pleistocene small scale push moraine in eastern poland new insight into paleoenvironmental conditions at the margin of an advancing ice lobe abstract recent studies of push moraines have focused on the interplay between the dynamics of ice margins and the environmental variables of the foreland into which they advance these studies showed that the spatial distribution geometry and style of the glaciotectonic deformation of push moraines are controlled by ice induced stresses the strain rate the rheology of the deposits and hydraulic conductivity in this work we provide new insight into this interplay at a small spatio temporal scale specifically the ancient glacial system of the liwiec ice lobe within the younger saalian ice sheet in eastern poland the paleoenvironmental variables that are analysed here refer to the dynamics of the hydrological processes that affected the patterns and sediment deposition rate on the terminoglacial fan and the resulting mechanical stratigraphy and hydraulic conductivity of the foreland we document the progradational sequence of the fan deposits that developed as a result of the ice lobe thickening and the steepening of its stationary front the sedimentary features of the fan the lithology of its basement and the hydraulic conductivity of the foreland strongly influenced the geometry and kinematics of fold growth during the advance of the ice lobe the predominance of flexural slip and the development of fractures including fold accommodation faults were interpreted to be an effect of buckle folding due to horizontal shortening induced by ice advance the partial overriding of the push moraine by the ice lobe and thus the submarginal conditions for deformation were inferred from the significant hinge migration and internal deformation of the strata under undrained conditions in one of the folds the synfolding deposition pattern of the fan growth strata allowed us to suggest that the push moraine was probably formed by a sustained advance rather than surge

early holocene glacier fluctuations in krundalen south central norway palaeoglacier dynamics and palaeoclimate krundalen a valley occupied by three eastern outlet glaciers of the jostedalsbre ice cap contains three groups of moraines two of which are outside the dated neoglacial little ice age lia l

geochemistry of the active azufre planchon peteroa volcanic complex chile 35 15 s evidence for multiple sources and processes in a cordilleran arc magmatic system

characteristics of recessional moraines at a temperate glacier in se iceland insights into patterns rates and drivers of glacier retreat icelandic glaciers are sensitive to climate variability on short term timescales owing to their north atlantic maritime setting and have been undergoing ice marginal retreat since the mid 1990s recent patterns rates and drivers of ice frontal retreat at skalafellsjokull se iceland are examined using small scale recessional moraines as a geomorphological proxy these small scale recessional moraines exhibit distinctive sawtooth planform geometries and are constructed by a range of genetic processes associated with minor ice margin re advance including i combined push squeeze mechanisms ii bulldozing of pre existing proglacial material and iii submarginal freeze on remote sensing investigations and lichenometric dating highlight sequences of annually formed recessional moraines on the northern and central parts of the foreland conversely moraines are forming on a sub annual timescale at the southeastern skalafellsjokull margin using annual moraine spacing as a proxy for annual ice margin retreat rates imrrs we demonstrate that prominent periods of glacier retreat at skalafellsjokull are coincident with those at other icelandic outlet glaciers as well as those identified at greenlandic outlet glaciers analysis of imrrs and climate data suggests summer air temperature sea surface temperature and the north atlantic oscillation have an influence on imrrs at skalafellsjokull with the glacier appearing to be most sensitive to summer air temperature on the basis of further climate data analyses we hypothesise that sea surface temperature may drive air temperature changes in the north atlantic region which in turn forces imrrs the increase in sea surface temperature over recent decades may link to atmospheric driven variations in north atlantic subpolar gyre dynamics

the formation of sawtooth moraine ridges in bodalen western norway abstract the forefield of the bodalsbreen glacier western norway exhibits a prominent set of end moraines the outermost one deposited at the little ice age lia maximum a d 1755 is smooth continuous and arcuate thus reflecting an even ice front in contrast subsequently formed moraines deposited a d 1767 1930 show a striking sawtooth morphology in an attempt to elucidate the formation processes responsible for this complex landform assemblage we have employed several methods of investigation including geomorphological mapping sedimentological studies and ground penetrating radar gpr in general the detailed formation processes of all moraines include bulldozing and thrusting furthermore the sediment composition and structure are similar for all the moraines containing recycled diamicton the remaining major factor influencing the moraine morphology thus seems to be the shape of the glacier front due to the distinctive geometry of the bodalen valley the former glacier underwent strong changes of its transverse stress field in the part where the valley was wider splaying radial crevasses developed further downvalley where the valley again narrowed these crevasses were closed as previous studies have concluded the change in valley morphology to a large extent explains the distinct morphology of the bodalen valley moraines this notion is further corroborated by studying sawtooth or sawtooth like moraines elsewhere where valley geometry also seems to have been a major contributing factor for moraine morphology

combining ash analyses with remote sensing to identify juvenile magma involvement and fragmentation mechanisms during the 2018 19 small eruption of peteroa volcano southern andes abstract the planchon peteroa volcanic complex ppvc is located on the border of chile and argentina and is one of the most active volcanic systems in the andes holocene activity has included magma water interaction with an evolving series of crater lakes mainly sourced from peteroa volcano this study examines data from the 2018 19 eruption together with the volcanic history of the ppvc to elucidate the complex interplay between magmatic activity and summit water and ice from february 2016 to mid 2019 three seismic swarms occurred in the ppvc preceding the explosive eruption from september 2018 to april 2019 the activity originated from a small vent nested within the easternmost crater the most active portion of the complex peteroa the explosions interacted with a crater lake producing ash plumes up to 2 km above the crater and building a small tephra cone to investigate the eruption mechanisms we performed remote sensing analysis of plume dispersal thermal anomalies and ground deformation and characterized the volcanic products including grain size componentry morphology internal textures composition and mineralogy our results suggest that the precursory seismicity beginning in 2016 was related to the intrusion of a new magma batch that reached the surface during the 2018 19 eruption the eruption was also preceded by thermal anomalies geomorphic changes and increased hydrothermal activity at the surface though without any ground deformation recognized through radar interferometry insar the eruption initially produced predominantly recycled ash phreatic activity then evolved to increasing proportions of juvenile magma phreatomagmatic by april 2019 the juvenile clasts had a trachyandesite composition 59 wt sio2 with vesicular and dense scoria containing plagioclase and pyroxene the ash surfaces show external quenching cracks and step fractures consistent with phreatomagmatic fragmentation within the active crater lake textural characteristics also point to a slowly ascending batch of magma that was relatively viscous by the time it interacted with water in the crater lake notably these juvenile particles are distinctive from the pre 2018 products ash erupted from 2010 11 did not contain recognizable juvenile material and is inferred to have been a mainly phreatic eruption our findings suggest that the interplay between phreatic and phreatomagmatic eruptions fed by small magma batches intruding at shallow levels characterize much of the eruptive behavior of the ppvc during the last three decades multi parametric assessment is a powerful tool to discriminate between phreatic and phreatomagmatic eruptions

the little ice age glacier advance in the central andes 35 s argentina abstract this paper documents the occurrence of the little ice age lia in the el azufre and el penon glaciers at 35 s and in the las choicas and las damas glaciers at 34 55 s in the headwaters of the rio grande basin in the central andes of argentina moraine morphology stratigraphic relationships radiocarbon ages obtained from peat on these glacial deposits and the proximity to the active glaciers enabled us to reconstruct the lia advance in this area the lia maximum advance occurred between cal yr 1550 and 1720 ad and a readvance occurred around cal yr 1830 ad in addition glacier fluctuations of the las vacas and gussfeltd glaciers 33 s and el penon and el azufre glaciers were documented from the end of the 19th century to the present based on historical and aerial photographs and satellite images the glaciers showed a marked retreat during 1894 2007 minor readvances occurred in the 1980s and 1990s which could be related with strong warm enso events during these decades our results are consistent with observations made by other authors in the region

the harbour of elaia a palynological archive for human environmental interactions during the last 7500 years abstract elaia the harbour city for ancient pergamon western turkey was investigated using geoarchaeological methods the rise and fall of elaia were closely linked to the flourishing period of pergamon which ruled wide parts of today s western turkey in hellenistic times in the framework of this research the palynological analysis of a 9 m sediment core ela 70 retrieved from the enclosed harbour of the city was carried out to reconstruct the vegetation and environmental history of the wider gulf of elaia region an age depth model based on 11 calibrated radiocarbon ages starting from 7 5 ka bp provides the basis for the high resolution study of sediments from the hellenistic period as well as before and after the lower part of the pollen diagram is characterised by high percentages of deciduous oaks and pines suggesting the dominance of open forests close to the coring site the change from oak forests to a cultural landscape with olive pistachio walnut and grape started around 850 bc reaching a maximum ca 250 bc and continuing to ca ad 800 this period is characterised by increase of fire activity soil erosion intensity and pastoral farming such long lasting intensive land use likely led to the climax ecosystem turnover from open deciduous oak forests to pine stands while salt marshes developed around the coring site the discovery of the dinoflagellate cysts of peridinium ponticum a black sea endemic species in the harbour of elaia evidences maritime trade between the aegean sea and the black sea its first occurrence coincides with the time of the mithridatic wars 1st century bc in conclusion palynological data in addition to historical and archaeological records provide a deeper insight into human environmental interactions as derived from the geoarchaeological archive of the harbour of elaia

multiproxy assessment of holocene relative sea level changes in the western mediterranean sea level variability and improvements in the definition of the isostatic signal abstract a review of 917 relative sea level rsl data points has resulted in the first quality controlled database constraining the holocene sea level histories of the western mediterranean sea spain france italy slovenia croatia malta and tunisia we reviewed and standardized the geological rsl data points using a new multi proxy methodology based on 1 modern taxa assemblages in mediterranean lagoons and marshes 2 beachrock characteristics cement fabric and chemistry sedimentary structures and 3 the modern distribution of mediterranean fixed biological indicators these rsl data points were coupled with the large number of archaeological rsl indicators available for the western mediterranean we assessed the spatial variability of rsl histories for 22 regions and compared these with the ice 5g vm2 gia model in the western mediterranean rsl rose continuously for the whole holocene with a sudden slowdown at 7 5 ka bp and a further deceleration during the last 4 0 ka bp after which time observed rsl changes are mainly related to variability in isostatic adjustment the sole exception is southern tunisia where data show evidence of a mid holocene high stand compatible with the isostatic impacts of the melting history of the remote antarctic ice sheet our results indicate that late holocene sea level rise was significantly slower than the current one first estimates of gia contribution indicate that at least in the northwestern sector it accounts at least for the 25 30 of the ongoing sea level rise recorded by mediterranean tidal gauges such contribution is less constrained at lower latitudes due to the lower quality of the late holocene index points future applications of spatio temporal statistical techniques are required to better quantify the gradient of the isostatic contribution and to provide improved context for the assessment of 20th century acceleration of mediterranean sea level rise

demise of a harbor a geochemical chronicle from ephesus a b s t r a c t at the end of the first century bc ephesus became the roman capital of asia minor and the most important commercial religious and cultural center of the region in order to evaluate the status of anthropogenic fluxes in the port of ephesus a 12 m long sediment core drilled in the roman basin was investigated to shed light on the paleo environmental evolution of the harbor using grain size distri bution analysis 14 c ages major and trace element geochemistry and pb isotope compositions with the help of complementary sedimentological data and principal component analysis five distinct units were identified which together reflect the different stages of water history in the harbor among the major disruptive events affecting the port were earthquakes and military events both of which were partic ularly effective at destroying the water distribution system seasonal floods of the cayster river kucuk menderes were the major source of the silt that progres sively infilled the harbor silting in was further enhanced by the westward migration of the river mouth a single major disruptive event located at 550 cm core depth and heralding the development of anoxia in the harbor marks the end of the dynamic regime that otherwise controlled the harbor water throughout the roman empire period this remarkable event may correspond to a major disruption of the aqueduct system or to a brutal avulsion of the cayster river bed it clearly represents a major disturbance in the history of life at ephesus it is poorly dated but probably occurred during the reign of augustus or shortly after lead isotope and trace metal evidence suggest that in the four bottom units pollution was subdued with respect to other pb metal inputs presumably those from aqueducts and natural karstic springs near the top of the core which coincides with harbor abandonment and the more recent period anthropogenic pb contam ination is clearly visible in both pb abundances and isotopic compositions

the sedimentary and structural evolution of a recent push moraine complex holmstrombreen spitsbergen abstract the glacier holmstrombreen in spitsbergen surged into the ice contact scarp of a proglacial outwash sequence at some time during its neoglacial maximum the outwash sediments were pushed along a decollement to produce a moraine in which deformation extended for 1 5 km beyond the furthest extent of the glacier front the style of folding and faulting and the nature of the pre syn and post tectonic sedimentary sequence across the whole push moraine is described from a continuously exposed section of the push moraine which extends from its proximal to distal extremities the precise extent of incremental compressive shortening of the pushed sediments of some 900 m is established the depth to the underlying decollement is inferred to be an average of about 30 m indicating that stresses and movement were transmitted through a thin nappe with an aspect ratio of about 1 in 30 it is suggested that this nappe was frozen and that an artesian water pressure head of 60 m immediately beneath it reduced friction along its base to a very low value it is calculated that a glacially generated force of about 1 5 10 7 kn was responsible for pushing the sediment nappe the nature of the glacially controlled groundwater flow system rather than the magnitude of longitudinal forces generated by the glacier is the principle determinant of large scale push moraine characteristics the changing ice topography produced by the pushing event during the surge and in the post surge decay had a major influence on the evolution of the meltwater drainage system and the style of fluvial sedimentation the structure sedimentary architecture and evolution of the whole glacitectonic fluvial complex can best be understood by considering the impact of the surge on a complete outwash system it is suggested that the setting and processes which produced the holmstrombreen push moraine could account for many broad multi ridge and fold push moraines which formed proglacially and that the thickness of original sediments above the decollement can be a guide to the thickness of contemporary permafrost

modern sedimentation in the n w aegean sea abstract the area under investigation is located within 22 45 to 23 45 e and from 39 15 to 40 15 n sedimentological bathymetric and shallow geophysical data were collected from here during the 7 78 cruise of r r s shackleton twenty seven sea bed surface samples were collected using a day grab from different environments these were analysed for grain size distribution carbonate content and clay mineralogy on the basis of the bathymetric and shallow geophysical data the area has been classified into five major physiographic environments according to their bathymetry and topography 1 shelf thermaicon plateau 2 slope 3 marginal plateau 4 the canyon system and valleys and 5 sporades basin based on the sedimentological analyses the surface sediments have been classified into four major provinces as follows 1 province 1 shelf muds 2 province 2 muddy sands 3 province 3 outer margin muds and 4 province 4 outer shelf shelf break it is concluded that modern sedimentation in the n w aegean sea is dominated by the terrigenous river inputs and by the circulation of both high and low salinity masses

sedimentary imprints of former ice sheet margins insights from an end ordovician archive sw libya fromthe proterozoic to the quaternary the evolution of the earthwas characterised by recurrent periods of glaciation however the margins of many ancient ice sheets are poorly defined on palaeogeographic reconstructions the extent and outlines of ancient ice sheets can be better understood through careful documentation of sediments deposited at the ice sheet margin an outstanding example is provided herein based on an end ordovician archive in libya tihemboka area murzuq basin the four sets of structures include i subglacial glaciotectonic structures and soft sediment deformations from flowing glacier ice such as intraformational glacial striae intraformational deformation shear planes sheath folds normal microfaults and large scale glaciotectonic folds and thrusts ii structures resulting from overpressured subglacial meltwater flows such as clastic dykes and tunnel valleys iii proglacial depositional structures and facies related to highmagnitude meltwater floods such as sandstone intraclasts large scale bedforms resulting from supercritical flows climbing dune cross stratification and kettle holes and iv deformation structures resulting from free floating and nonglacier ice such as ice keel scours and ice crystal marks such a set of structures points to an ice marginal essentially continental depositional setting and provides an excellent suite of criteria to identify margins of ancient ice sheets in the stratigraphic record at a regional scale a reconstruction through time and space of the related depositional wedge is proposed this corresponded to a seismic scale n120 m in thickness 40 km in length ice marginal wedge in front of an essentially warm based ice sheet inducing concomitant large scale glaciotectonic deformation glacial basin and tunnel valley downcuttings the related ice front was associated with high energy meltwater flows feeding a network of deeply incised proglacial channels downstream and beyond them a fluvioglacial deltaic system shallow ice marginal permafrost most likely affected the depositional wedge at a larger scale the tihemboka ice marginal wedge is interpreted as related to a stillstand period over the gondwana platform developed over an estimated interval of a few thousands of years based on these data the conditions that arose in a particularly favourable context for the development the preservation and the identification of ice marginal wedges in the geological record are reviewed significant meltwater derived sediment deposition and aggradation in an accommodation space resulting either from preglacial inheritance glacial downcuttings and or glacio isostatic lithospheric flexure or active tectonic subsidence 1 myr are required for their formation and subsequent preservation

in search of pollentia s southern harbour geoarchaeological evidence from the bay of alcudia mallorca spain the roman city of pollentia was founded on the north eastern coast of mallorca balearic archipelago after the roman conquest of the island in 123 bce there is evidence that the city had two harbours a small harbour located to the north whereas the main harbour was located to the south of pollentia our study focuses on the southern harbour on a coastal plain in proximity to the ancient city four sedimentary cores were taken and bio sedimentological analysis was performed here we describe the palaeogeographical changes in this area evolving from an open lagoon environment between ca 3200 and ca 500 cal years bce to a semi enclosed lagoon during roman times progressively the lagoon became silted and was isolated from the sea by the development of a large sand spit probably during the second half of the first millennium ce we also discuss the water depth linked to the palaeosea level which is important in defining the possible ancient harbour location

the fluvial evolution of the holocene nile delta abstract the evolution of the nile delta the largest delta system in the mediterranean sea has both high palaeoenvironmental and archaeological significance a dynamic model of the landscape evolution of this delta system is presented for the period c 8000 4500 cal bp analysis of sedimentary data and chronostratigraphic information contained within 1640 borehole records has allowed for a redefinition of the internal stratigraphy of the holocene delta and the construction of a four dimensional landscape model for the delta s evolution through time the mid holocene environmental evolution is characterised by a transition from an earlier set of spatially varied landscapes dominated by swampy marshland to better drained more uniform floodplain environments archaeologically important pleistocene inliers in the form of sandy hills protruding above the delta plain surface known as turtlebacks also became smaller as the delta plain continued to aggrade while the shoreline and coastal zone prograded north these changes were forced by a decrease in the rate of relative sea level rise under high rates of sediment supply this dynamic environmental evolution needs to be integrated within any discussion of the contemporary developments in the social sphere which culminated in the emergence of the ancient egyptian state c 5050 cal bp

evolution of high arctic glacial landforms during deglaciation abstract glacial landsystems in the high arctic have been reported to undergo geomorphological transformation during deglaciation this research evaluates moraine evolution over a decadal timescale at midtre lovenbreen svalbard this work is of interest because glacial landforms developed in svalbard have been used as an analogue for landforms developed during pleistocene mid latitude glaciation ground penetrating radar was used to investigate the subsurface characteristics of moraines to determine surface change a lidar topographic data set obtained 2003 and a uav derived obtained 2014 digital surface model processed using structure from motion sfm are also compared evaluation of these data sets together enables subsurface character and landform response to climatic amelioration to be linked ground penetrating radar evidence shows that the moraine substrate at midtre lovenbreen includes ice rich radar velocities of 0 17 m ns 1 and debris rich radar velocities of 0 1 0 13 m ns 1 zones the ice rich zones are demonstrated to exhibit relatively high rates of surface change mean thresholded rate of 4 39 m over the 11 year observation period however the debris rich zones show a relatively low rate of surface change mean thresholded rate of 0 98 m over the 11 year observation period and the morphology of the debris rich landforms appear stable over the observation period a complex response of proglacial landforms to climatic warming is shown to occur within and between glacier forelands as indicated by spatially variable surface lowering rates landform response is controlled by the ice debris balance of the moraine substrate along with the topographic context such as the influence of meltwater site specific characteristics such as surface debris thickness and glaciofluvial drainage are therefore argued to be a highly important control on surface evolution in ice cored terrain resulting in a diverse response of high arctic glacial landsystems to climatic amelioration these results highlight that care is needed when assessing the long term preservation potential of contemporary landforms at high arctic glaciers a better understanding of ice cored terrain facilitates the development of appropriate age and climatic interpretations that can be obtained from palaeo ice marginal landsystems

late holocene erosion of the canopic promontory nile delta egypt abstract the mouths of the nile delta are sensitive coastal areas their geomorphology primarily being mediated by relative sea level rise and sediment supply to further document the holocene evolution of the nile s canopic mouth a core was taken from the southern shores of abu qir bay close to the ancient canopic channel core bio sedimentology and chronostratigraphy highlight four stages of marine incursion which are juxtaposed upon the general progradation trend of the nile coast in this area compiled age depth points from sediment cores taken in abu qir bay underscore two phases of negative sediment budget at the canopic mouth 1 a first period between 3 5 and 2 ka cal yr bc probably in relation to the well documented mid to late holocene decline in nile flow and 2 a second phase after 0 5 ka cal ad linked to a decline in canopic sediment supply to the coastal area and concomitant with the development of the rashid branch the erosion and reworking of material flattened and lowered the promontory surface by up to 4 m the submersion of the canopic promontory was completed by relative sea level rise primarily controlled by the compaction and liquefaction of unconsolidated lagoonal muds the lowering of the canopic mouth led to the submersion of two ancient estuarine harbor cities known as east canopus and herakleion whose remains lie 4 7 m below present mean sea level it is argued that the subsidence of the two cities cannot explain their abandonment during the late 7th early 8th century ad taking into account the regional occupation pattern during antiquity rather the longevity of the two cities spanning more than 13 centuries shows that adaptation to coastal risks including erosion subsidence and high energy events like storms or tsunamis was the rule

geochemistry of fluid discharges from peteroa volcano argentina chile in 2010 2015 insights into compositional changes related to the fluid source region s abstract this study presents the first geochemical data of fluid discharges collected from february 2010 to march 2015 from the planchon peteroa azufre volcanic complex ppavc located in the transitional southern volcanic zone tsvz at the border between argentina and chile during the study period from january 2010 to july 2011 peteroa volcano experienced phreatic to phreatomagmatic eruption possibly related to the devastating maule earthquake occurred on february 27 2010 the compositional dataset includes low temperature from 43 2 to 102 c gas discharges from i the summit of peteroa volcano and ii the se flank of azufre volcano both marked by a significant magmatic fluid contribution as well as bubbling gases located at the foothill of the peteroa volcanic edifice which showed a chemical signature typical of hydrothermal fluids in 2012 strong compositional changes affected the peteroa gases from the summit area the acidic gas species especially so 2 increased suggesting an input of fluids from magma degassing nevertheless the r ra and 13 c co 2 values decreased which would imply an enhanced contribution from a meteoric hydrothermal source in 2014 2015 the chemical and isotopic compositions of the 2010 2011 gases were partially restored the anomalous decoupling between the chemical and the isotopic parameters was tentatively interpreted as produced by degassing activity from a small batch of dacitic magma that in 2012 masked the compositional signature of the magmatic fluids released from a basaltic magma that dominated the gas chemistry in 2010 2011 this explanation reliably justifies the observed geochemical data although the mechanisms leading to the change in time of the dominating magmatic fluid source are not clear at this regard a geophysical survey able to provide information on the location of the two magma batches could be useful to clarify the possible relationships between the compositional changes that affected the peteroa fluid discharges and the 2010 2011 eruptive activity

push moraines and glacier contact fans in marine and terrestrial environments the local climatic regime and the mass balance state are important determinants of the dynamics of terrestrial and marine glacier fronts which in turn determine the sediments and landforms produced at the glacier front many modern glaciers undergoing overall retreat in areas of maritime climate produce winter push moraines during a late winter readvance followed by a summer retreat whilst in more continental regions no significant winter readvance occurs and annual push moraines are absent the frontal dynamics which lead to these changes are analysed and the form structure sequence and field relations of both terrestrial and marine push moraines are described from iceland spitsbergen and baffin island long term changes in mass balance leading to major glacier advances or readvances also generate large push moraines in terrestrial environments push moraine formation is accompanied by uplift rejuvenation and down cutting of outwash systems whose sediments become closely associated with glaciotectonic structures which permit pre syn and post tectonic sequences to be identified the development of ice marginal fan moraine complexes is modelled as a function of the relative magnitude of two parameters the velocity of ice movement and the calving rate a high ice velocity just exceeded by the calving rate gives closely spaced push moraines and confluent ice marginal fans a high velocity far exceeded by the calving rate produces closely spaced moraines but separate ice marginal fans a low ice velocity in combination with a high calving rate results in well separated and feebly developed push moraines while a low ice velocity and a low calving rate produces feeble push moraines and coalescent fans

geomorphological investigation of multiphase glacitectonic composite ridge systems in svalbard some surge type glaciers on the high arctic archipelago of svalbard have large glacitectonic composite ridge systems at their terrestrial margins these have formed by rapid glacier advance into proglacial sediments during the active surge phase creating multicrested moraine complexes such complexes can be formed during single surge advances or multiple surges to successively less extensive positions the few existing studies of composite ridge systems have relied on detailed information on internal structure and sedimentology to reconstruct their formation and links to surge processes however natural exposures of internal structure are commonly unavailable and the creation of artificial exposures is often problematic in fragile arctic environments to compensate for these issues we investigate the potential for reconstructing composite ridge system formation based on geomorphological evidence alone focusing on clear morphostratigraphic relationships between ridges within the moraine complex and relict meltwater channels outwash fans based on mapping at the margins of finsterwalderbreen in van keulenfjorden and gronfjordbreen in gronfjorden we show that relict meltwater channels that breach outer parts of the composite ridge systems are in most cases truncated upstream within the ridge complex by an inner pushed ridge or ridges at their ice proximal extents our interpretation of this relationship is that the entire composite ridge system is unlikely to have formed during the same glacier advance but is instead the product of multiple advances to successively less extensive positions whereby younger ridges are emplaced on the ice proximal side of older ridges this indicates that the finsterwalderbreen composite ridge system has been formed by multiple separate advances consistent with the cyclicity of surges being able to identify the frequency and magnitude of former surges is important as it provides insight into the past behaviour of surge type glaciers and if absolute dating is possible allows for the assessment of surge type glacier response to climate change on decadal to centennial timescales although further investigations into the internal structure of these deposits should be sought where possible our study demonstrates that geomorphology could be an invaluable tool for reconstructing the formation of composite ridge systems

surges of glaciers in iceland surges are common in all the major ice caps in iceland and historical reports of surge occurrence go back several centuries data collection and regular obser vationover thelast several decadeshave permitteda detailed descriptionof several surges fromwhich it is possible to generalize onthe nature of surging in icelandic glaciers com bining the historical records of glacier front variations and recent field research we sum marize the geographic distribution of surging glaciers their subglacial topography and geology the frequency andduration of surges changes in glacier surface geometry during the surge cycle and measured velocity changes comparedto calculatedbalance velocities wenotetheindicatorsofsurgeonsetanddescribechangesinice waterandsedimentfluxes duringa surge surgesaccomplishasignificantfractionofthetotalmasstransportthrough the main outlet glaciers of ice caps in iceland and have important implications for their hydrology ouranalysisof the data suggeststhat surge type glaciersin icelandarecharac terizedbygentlysloping surfacesandthatthey movetoo slowlytoremain inbalance given their accumulation rate surge frequency is neither regular nor clearly related to glacier size or massbalance steeply sloping glaciers whetherhard or soft bedded seemto move sufficiently rapidly to keep inbalance with the annual accumulation

sedimentological and deformational criteria for discriminating subglaciofluvial deposits from subaqueous ice contact fan deposits a pleistocene example ireland a pit located near ballyhorsey 28 km south of dublin eastern ireland displays subglacially deposited glaciofluvial sediments passing upwards into proglacial subaqueous ice contact fan deposits the coexistence of these two different depositional environments at the same location will help with differentiation between two very similar and easily confused glacial lithofacies the lowermost sediments show aggrading subglacial deposits indicating a constrained accommodation space mainly controlled by the position of an overlying ice roof during ice bed decoupling these sediments are characterized by vertically stacked tills with large lenses of tabular to channelized sorted sediments the sorted sediments consist of fine grained laminated facies cross laminated sand and channelized gravels and are interpreted as subglaciofluvial sediments deposited within a subglacial de coupled space the subglaciofluvial sequence is characterized by glaciotectonic deformation structures within discrete beds triggered by fluid overpressure and shear stress during episodes of ice bed recoupling clastic dykes and folds the upper deposits correspond to the deposition of successive hyperpycnal flows in a proximal proglacial lake forming a thick sedimentary wedge erosively overlying the subglacial deposits gravel facies and large scale trough bedding sand are observed within this proximal wedge while normally graded sand beds with developed bedforms are observed further downflow the building of the prograding ice contact subaqueous fan implies an unrestricted accommodation space and is associated with deformation structures related to gravity destabilization during fan spreading normal faults this study facilitates the recognition of subglacial submarginal depositional environments formed in part during localized ice bed coupling episodes in the sedimentary record the sedimentary sequence exposed in ballyhorsey permits characterization of the temporal framework of meltwater production during deglaciation the impact on the subglacial drainage system and the consequences on the irish sea ice stream flow mechanisms

the mount kozak magmatic complex western anatolia abstract the mount kozak igneous complex is located close to the towns of ayvalik bergama and burhaniye in the western anatolia turkey magmatic activity occurred during the late oligocene early miocene beginning with the emplacement of the kozak pluton sheet intrusive rocks formed around it coevally they are surrounded by the volcanic rocks partly contemporaneously with the emplacement of the granitic rocks during the early miocene the upper oligocene lower miocene magmatic rocks of the kozak region are represented by a high k calc alkaline suite of predominantly intermediate and acidic composition their geochemical characteristics suggest that the magmas are hybrid and were formed from a similar source representing mantle derived magmas contaminated by crustal materials the cogenetic plutonic rocks the hypabyssal rocks and the overlying volcanic associations are related to one another in space and time and appear to have been connected to a shallow level granitic intrusion in a caldera collapse setting the calc alkaline magmatic activity waned during the middle miocene when the volcanism was rejuvenated during the late miocene pliocene alkaline basalt lavas were formed as fissure eruptions

high resolution satellite and airborne thermal infrared imaging of precursory unrest and 2009 eruption at redoubt volcano alaska abstract a combination of satellite and airborne high resolution visible and thermal infrared tir image data detected and measured changes at redoubt volcano during the 2008 2009 unrest and eruption the tir sensors detected persistent elevated temperatures at summit ice melt holes as seismicity and gas emissions increased in late 2008 to march 2009 a phreatic explosion on 15 march was followed by more than 19 magmatic explosive events from 23 march to 4 april that produced high altitude ash clouds and large lahars two or three lava domes extruded and were destroyed between 23 march and 4 april after 4 april the eruption extruded a large lava dome that continued to grow until at least early july 2009

landform characterization using geophysics recent advances applications and emerging tools abstract this paper presents an overview of the strengths and limitations of existing and emerging geophysical tools for landform studies the objectives are to discuss recent technical developments and to provide a review of relevant recent literature with a focus on propagating field methods with terrestrial applications for various methods in this category including ground penetrating radar gpr electrical resistivity er seismics and electromagnetic em induction the technical backgrounds are introduced followed by section on novel developments relevant to landform characterization for several decades gpr has been popular for characterization of the shallow subsurface and in particular sedimentary systems novel developments in gpr include the use of multi offset systems to improve signal to noise ratios and data collection efficiency amongst others and the increased use of 3d data multi electrode er systems have become popular in recent years as they allow for relatively fast and detailed mapping novel developments include time lapse monitoring of dynamic processes as well as the use of capacitively coupled systems for fast non invasive surveys em induction methods are especially popular for fast mapping of spatial variation but can also be used to obtain information on the vertical variation in subsurface electrical conductivity in recent years several examples of the use of plane wave em for characterization of landforms have been published seismic methods for landform characterization include seismic reflection and refraction techniques and the use of surface waves a recent development is the use of passive sensing approaches the use of multiple geophysical methods which can benefit from the sensitivity to different subsurface parameters is becoming more common strategies for coupled and joint inversion of complementary datasets will once more widely available benefit the geophysical study of landforms three cases studies are presented on the use of electrical and gpr methods for characterization of landforms in the range of meters to 100 s of meters in dimension in a study of polygonal patterned ground in the saginaw lowlands michigan usa electrical resistivity tomography was used to characterize differences in subsurface texture and water content associated with polygon swale topography also a sand filled thermokarst feature was identified using electrical resistivity data the second example is on the use of constant spread traversing cst for characterization of large scale glaciotectonic deformation in the ludington ridge michigan multiple cst surveys parallel to an 60 m high cliff where broad 100 m synclines and narrow clay rich anticlines are visible illustrated that at least one of the narrow structures extended inland a third case study discusses internal structures of an eolian dune on a coastal spit in new zealand both 35 and 200 mhz gpr data which clearly identified a paleosol and internal sedimentary structures of the dune were used to improve understanding of the development of the dune which may shed light on paleo wind directions

glacial geomorphological mapping a review of approaches and frameworks for best practice geomorphological mapping is a well established method for examining earth surface processes and landscape evolution in a range of environmental contexts in glacial research it provides crucial data for a wide range of process oriented studies and palaeoglaciological reconstructions in the latter case providing an essential geomorphological framework for establishing glacial chronologies in recent decades there have been significant developments in remote sensing and geographical information systems gis with a plethora of high quality remotely sensed datasets now often freely available most recently the emergence of unmanned aerial vehicle uav technology has allowed sub decimetre scale aerial images and digital elevation models dems to be obtained traditional field mapping methods still have an important role in glacial geomorphology particularly in cirque glacier valley glacier and icefield ice cap outlet settings field mapping is also used in ice sheet settings but often takes the form of necessarily highly selective ground truthing of remote mapping given the increasing abundance of datasets and methods available for mapping effective approaches are necessary to enable assimilation of data and ensure robustness this paper provides a review and assessment of the various glacial geomorphological methods and datasets currently available with a focus on their applicability in particular glacial settings we distinguish two overarching work streams that recognise the different approaches typically used in mapping landforms produced by ice masses of different sizes i mapping of ice sheet geomorphological imprints using a combined remote sensing approach with some field checking where feasible and ii mapping of alpine and plateau style ice mass cirque glacier valley glacier icefield and ice cap geomorphological imprints using remote sensing and considerable field mapping key challenges to accurate and robust geomorphological mapping are highlighted often necessitating compromises and pragmatic solutions the importance of combining multiple datasets and or mapping approaches is emphasised akin to multi proxy approaches used in many earth science disciplines based on our review we provide idealised frameworks and general recommendations to ensure best practice in future studies and aid in accuracy assessment comparison and integration of geomorphological data these will be of particular value where geomorphological data are incorporated in large compilations and subsequently used for palaeoglaciological reconstructions finally we stress that robust interpretations of glacial landforms and landscapes invariably requires additional chronological and or sedimentological evidence and that such data should ideally be collected as part of a holistic assessment of the overall glacier system

coseismic slip distribution of the february 27 2010 mw 8 8 maule chile earthquake 1 static offsets produced by the february 27 2010 mw 8 8 maule chile earthquake as measured by gps and insar constrain coseismic slip along a section of the andean megathrust of dimensions 650 km in length 180 km in width gps data have been collected from both campaign and continuous sites sampling both the near field and far field alos palsar data from several ascending and descending tracks constrain the near field crustal deformation inversions of the geodetic data for distributed slip on the megathrust reveal a pronounced slip maximum of order 15 m at 15 25 km depth on the megathrust offshore lloca indicating that seismic slip was greatest north of the epicenter of the bilaterally propagating rupture a secondary slip maximum appears at depth 25 km on the megathrust just west of concepcion coseismic slip is negligible below 35 km depth estimates of the seismic moment based on different datasets and modeling approaches vary from 1 8 to 2 6 1022 n m our study is the first to model the static displacement field using a layered spherical earth model allowing us to incorporate both near field and far field static displacements in a consistent manner the obtained seismic moment of 1 97 1022 n m corresponding to a moment magnitude of 8 8 is similar to that obtained by previous seismic and geodetic inversions

taken from the sea reclaimed by the sea the fate of the closed harbour of elaia the maritime satellite city of pergamum turkey abstract during hellenistic times when the pergamenian kingdom was prospering pergamum was operating an important harbour used by merchants and military at the city of elaia this paper focuses on the development utilisation and decay of the closed harbour of elaia which is discussed in the context of the landscape evolution of the environs of the ancient settlement based on geoarchaeological archaeological and literary evidence the construction of two harbour moles in order to provide shelter against wave action and enemies can be attributed to the early hellenistic period geoelectric measurements revealed the construction profile of the moles coring evidence indicated that together with mole construction a greater area of the formerly shallow marine and sublittoral terrain was consolidated most probably to create space for harbour installations the closed harbour basin was used intensely during hellenistic and roman times later continued siltation hindered further usage in combination with the decline of the city of elaia in late antiquity this was the reason why the harbour was abandoned scenarios for the time of the maximum transgression of the sea around 2500 bc the early hellenistic times around 300 bc and late antiquity ad 500 are presented

late holocene shorelines in east attica greece abstract a coastal and submarine geomorphological investigation took place in the coasts of eastern attica aiming to identify palaeoshorelines former sea level positions were deduced from emerged and submerged tidal notches eight fossil shorelines were deduced in the study area two emerged ones at about 24 30 and 40 30 cm and six submerged ones at about 22 30 modern 40 30 60 30 80 30 130 30 and 460 30 cm it is worth mentioning that a rather different tectonic behavior may be distinguished between the south at1 at5 and the north at10 at28 part of the study area

the environs of elaia s ancient open harbour a reconstruction based on microfaunal evidence during hellenistic and roman times elaia the harbour city of ancient pergamum was an important place of trading and traffic intense mercantile and military activities are documented by literary sources and archaeological evidences geomagnetic and geoelectric investigations detected building structures close to the ancient coastline which are interpreted as ship sheds the aim of this study was to reconstruct the coastal evolution particularly with regard to harbour related facilities for that purpose a 10 m long sediment core was drilled in the area of the ancient open harbour immediately in front of the supposed ship sheds it was studied with the tools of micropalaeontology geophysics sedimentology and geochemistry to improve the reconstruction of the palaeoenvironmental conditions reference samples of modern environments of the area were analysed as indicated by marine ostracod and foraminifer taxa the sediment core shows from bottom to top that the initially fully marine conditions changed to a more restricted fauna indicative for a more sheltered bay with brackish waters this layer dates to hellenistic times it can however be shown that the siltation process had produced a lagoon system already several hundred years bc the elaia embayment was first used as a natural harbour it was equipped with breakwaters in the hellenistic period the progressive siltation caused the abandonment of the harbour in late roman times

polyphase glacigenic deformation in the waterloo moraine kitchener ontario canada abstract a sedimentological investigation of quaternary sediments in the waterloo moraine was conducted to characterize the nature of deformation in stratified sediments in the kieswetter holdings ltd aggregate quarry kitchener ontario highly deformed interbedded clay silt fine to very coarse grained sand and granular to cobble gravel is exposed in two sets of contiguous panels analysis of the sediment revealed five recognizable stratigraphic units 1 climbing ripple cross laminated silt 2 normally graded cobble gravel 3 cross bedded fine to coarse grained sand 4 interbedded clay silt and fine to very coarse grained sand with granules and 5 crudely channelized interbedded medium to very coarse grained sand and granule to pebble gravel these units suggest rapid deposition and fluctuating energy in a subaqueous environment prior to deformation deformation structures include normal faults with offsets ranging from 1 to 50 cm widespread occurrences of density driven ductile deformation ranging from 0 5 to 5 cm open to closed folds cm to m scale as well as isolated occurrences of overturned folding ranging in size from 0 5 cm to approximately 1 2 m abundant reverse faulting with offsets ranging from 0 5 to 7 cm average of 2 cm and widespread occurrences of boudinage bed attenuation and shear folds ranging in scale from 0 5 to 1 5 m were also observed the nature and scale of deformation structures suggest complex polyphase deformation of heterogeneous sediments related to rapid sedimentation sediment gravity flow active ice deformation and melting of buried ice in a dynamic subaqueous environment

glacial geological studies of surge type glaciers in iceland research status and future challenges abstract surging glaciers are potential analogues for land terminating palaeo ice streams and surging ice sheet lobes and research on surge type glaciers is important for understanding the causal mechanisms of modern and past ice sheet instabilities the geomorphic signatures left by the icelandic surge type glaciers vary and range from glaciotectonic end moraines formed by folding and thrusting crevasse squeeze ridges concertina eskers drumlins and fluted forefields to extensive dead ice fields and even drift sheets where fast ice flow indicators are largely missing we outline some outstanding research questions and review case studies from the surge type outlets of bruarjokull eyjabakkajokull and tungnaarjokull vatnajokull ice cap mulajokull and satujokull hofsjokull ice cap hagafellsjokull and su urjokull langjokull ice cap kaldalonsjokull leirufjar arjokull and reykjarfjar arjokull drangajokull ice cap as well as the surge type cirque glaciers in northern iceland we review the current understanding of how rapid ice flow is sustained throughout the surge the processes that control the development of the surge type glacier landsystem and the geological evidence of surges found in sediments and landforms we also examine if it is possible to reconstruct past surge flow rates from glacial landforms and sediments and scale up present day surge processes landforms and landsystems as modern analogues to past ice streams finally we also examine if there is a climate mass balance control on surge initiation duration and frequency

volcano surveillance using infrared cameras abstract volcanic eruptions are commonly preceded accompanied and followed by variations of a number of detectable geophysical and geochemical manifestations many remote sensing techniques have been applied to tracking anomalies and eruptive precursors and monitoring ongoing volcanic eruptions offering obvious advantages over in situ techniques especially during hazardous activity whilst spaceborne instruments provide a distinct advantage for collecting data remotely in this regard they still cannot match the spatial detail or time resolution achievable using portable imagers on the ground or aircraft hand held infrared camera technology has advanced significantly over the last decade resulting in a proliferation of commercially available instruments such that volcano observatories are increasingly implementing them in monitoring efforts improved thermal surveillance of active volcanoes has not only enhanced hazard assessment but it has contributed substantially to understanding a variety of volcanic processes drawing on over a decade of operational volcano surveillance in italy we provide here a critical review of the application of infrared thermal cameras to volcano monitoring following a summary of key physical principles instrument capabilities and the practicalities and methods of data collection we discuss the types of information that can be retrieved from thermal imagery and what they have contributed to hazard assessment and risk management and to physical volcanology with continued developments in thermal imager technology and lower instrument costs there will be increasing opportunity to gather valuable observations of volcanoes it is thus timely to review the state of the art and we hope thereby to stimulate further research and innovation in this area

an integrated approach to the study of glaciolacustrine landforms and sediments a case study from hagavatn iceland abstract this paper describes the landform assemblage associated with the neoglacial fluctuation of hagafellsjokull eystri into proglacial hagavatn iceland this landform assemblage is dominated by three components firstly a series of moraines formed both by thrusting within the glacier margin and by proglacial subglacial deformation the internal sedimentary architecture of these moraines ranges from stacked sediment slabs separated by listric thrusts to complexly folded and faulted sequences all in glaciolacustrine sediments the second component is a morainal bank and associated ice contact delta the morainal bank consists of a series of low amplitude ridges composed of laminated silts and clays which have been deformed proglacially during the neoglacial ice advance 1890 this morainal bank helped stabilise the 1890 ice limit within the proglacial lake and was the focus for subaqueous outwash first in the form of a subaqueous out wash fan and subsequently as an ice contact delta the third component is a series of lake bed kame terraces formed by rapid sedimentation in a canal like lake formed as the ice retreated away from the push moraines a range of glaciolacustrine facies is present within the lake bed kame terraces and the sedimentary architecture records a complex pattern of ice marginal oscillations and changes in lake level this detailed case study provides an important analogue for the interpretation of both glaciolacustrine and glaciomarine landform sediment assemblages of pleistocene age and illustrates a range of styles of glaciolacustrine sedimentation and glaciotectonic deformation

lithofacies types and vertical profile models an alternative approach to the description and environmental interpretation of glacial diamict and diamictite sequences abstract increased knowledge of modern glacial depositional environments has resulted in rapidly evolving classifications of glacial tills these are based to a large degree on theoretical considerations of likely depositional processes the classifications are sophisticated and more advanced than the establishment of simple field criteria whereby individual till facies can be identified in quaternary and pre quaternary successions this situation is compounded in many quaternary terrains by the continued description of tills in terms of laboratory derived analytical data only reflecting a traditional interest in stratigraphic correlation rather than reconstruction of depositional environment detailed sedimentological logging of lithofacies is rarely undertaken there is thus considerable confusion as to what is being described or sampled when analytical data are presented for many pleistocene tills the same remarks apply to pre pleistocene tillites a lithofacies code is presented here for the rapid description and visual appraisal of field sequences or drill cores containing unconsolidated diamicts or lithified diamictites the term till is not used as it has a strict genetic definition referring to direct aggregation and deposition by glacier ice use of a four part code in conjunction with codes already published for fluvial sediments allows fundamental field properties to be depicted independent of genetic terminology and provides a firm basis for subsequent environmental interpretation and analytical work the value of this approach is illustrated by comparing a representative suite of vertical profiles of diamict assemblages deposited by modern grounded glaciers with a classic late pleistocene glacigenic sequence at scarborough bluffs ontario

an updated database of holocene relative sea level changes in ne aegean sea abstract the reconstruction of holocene relative sea levels has several implications ranging from the investigation of coastal vertical movements to the calibration of earth rheology models and ice sheet reconstructions the north eastern aegean sea is among the tectonically complex sectors of the eastern mediterranean mainly influenced by the activity of the north anatolian fault in this paper we created a relative sea level rsl database by expanding upon the previous compilation with recently published geological and archaeological data we reconstruct the rsl history in those aegean coastal sectors located within the south marmara microplate a broad shear zone located between western anatolia and central greece and affected by dominant strike slip faulting at times combined with a normal component then we compared it with the rsl histories obtained for the surrounding coastal sectors the analysis of the database indicated that it is not possible to define a common holocene rsl curve for the entire ne aegean as rsl history here is majorly influenced by changes in deformation patterns in addition data in our database are consistent with a continuous rsl rise in the last 6 0 ka bp in the whole ne aegean sea and cannot support the hypothesis of a mid holocene rsl highstand in the area finally we present our best estimates of late holocene rates of rsl prior to any possible acceleration during the twentieth century in the broad area of ne aegean here we identified the fastest rising rate 0 9 mm a 1 in that sector whose active tectonic deformation is mainly controlled by the north anatolian fault activity

glaciotectonized quaternary sediments at dinas dinlle gwynedd north wales and their bearing on the style of deglaciation in the eastern irish sea abstract the sedimentology and structure of late quaternary sediments exposed in a coastal section at dinas dinlle north wales are described the deposits from two small hills the northern one being more prominent and containing northward dipping units of gravel and diamicton bounded by clay lined thrust faults the southern hill comprises complex folded sands and gravels overlying a basal till surface high resolution seismic surveys along the beach 50 m west of the cliffs show a roughly horizontal rockhead lying some 35 m below beach level and demonstrate that thrust faults penetrate the entire quaternary sequence to a detachment immediately above rockhead thrust units in the exposed cliff section show excellent correlation with the seismic sequence 50 m to the west indicating a strike of 080 260 balanced cross section techniques were applied to an initial simple layered sequence comprising a lower irish sea till overlain by a coarsening upwards sand to gravel unit followed by upper till mixed lithology including welsh and northern provenance and finally an upper gravel unit shortening of approximately 54 is estimated within the thrust sequence it is concluded that the two isolated hills at dinas dinlle are erosional remnants of a formerly more extensive push moraine extending westwards into caernarfon bay which has now been truncated by coastal retreat deglaciation of the area was interrupted by ice sheet readvance towards 170 across a proglacial surface

theory of glacial erosion transport and deposition as a consequence of subglacial sediment deformation a theory of erosion transport and deposition of unlithified sediments by glaciers is presented it predicts the large scale areal distribution of zones and rates of erosion and deposition in time and space through a complete glacial cycle together with the resultant intensity of large scale lincations drumlins which will be incised in the landscape the theory also predicts the dispersal patterns of subglacial lithologies together with the form of dispersal trains derived from distinctive sources and the vertical and horizontal distribution of lithologies within a till it predicts major erosional discontinuities within tills and the formation of boulder pavements it suggests that the dominant proportion of the lowland tills produced by pleistocene mid latitude ice sheets was generated by subglacial deformation and explains why they are predominantly fine grained the theory is based on an analysis of glacier dynamic processes and therefore can be used to infer the dynamic behaviour of former ice sheets from the distribution of tills and their lithologic composition

melt out till and ribbed moraine formation a case study from south sweden abstract hummocky moraine with dispersed agglomerations of ribbed moraine here named asnen type ribbed moraine forms a 20 40 km wide zone over smaland south sweden terminated to the north by a sharp boundary to streamlined terrain the hummocky ribbed moraine zone can be geomorphologically linked to the subaqueous goteborg moraine formed at an oscillation stand still phase during the deglaciation of the swedish west coast based on detailed sedimentological and structural investigations of ribbed moraine ridges it is concluded that diamict sequences and associated sorted sediment were deposited due to passive melt out from stagnant debris rich ice with synsedimentary deposition of sorted sediments preferentially at a melting ice bed interface to accommodate for the geomorphological expression such an interpretation further implies that debris rich ice formed in an intermediate adfreezing zone between ice at the pressure melting point and a frontal frozen zone at deglaciation basal debris rich ice was stacked into transversally arranged zones controlled moraine forming ribbed moraine embryos the active phase of ridge formation the stacked sequences of debris rich ice eventually melted out beneath a stable and melt retarding supraglacial ablation complex to form the final moraine ridges the passive phase of ridge formation in areas with no stable supraglacial ablation complex the resulting landform after final de icing was a hummocky moraine landscape internal composition of moraine hummocks suggests that most of them are composed of sediment gravity flow sediments intercalated with stream deposited sediments all resting on a platform of subglacial melt out till de icing of the zone now occupied by hummocky and ribbed moraine took a considerable time deglacial 14 c age differences from lake basins on either side of the geomorphic boundary to the streamlined terrain indicate a separation between active and stagnant ice along that boundary and that it took another 200 300 yr for the stagnant ice zone to melt during the final formation of present day landforms

unravelling fluvial deposition and pedogenesis in ephemeral stream deposits in the vicinity of the prehistoric rock shelter of ifri n ammar ne morocco during the last 100 ka abstract our study focuses on the ephemeral stream deposits of wadi selloum to identify phases of morphodynamic stability pedogenesis and activity flooding in the direct vicinity of the rock shelter of ifri n ammar ne morocco as one of the oldest settlement sites of anatomically modern humans amh in north africa ifri n ammar documents periodical occupations since 170 ka since the discontinuous settlement record may reflect climate forcing with subsequent landscape changes we aim at reconstructing the palaeoenvironmental variability recorded in the ephemeral stream deposits in addition to the use of micromorphological sedimentological geochemical and mineralogical methods the geochronological framework of ephemeral stream deposits was established by the application of different luminescence dating techniques the deposition ages between 102 8 ka and 1 3 0 2 ka span different morphodynamically stable and active phases periods of enhanced aggradation occurred around 100 ka 75 ka 55 ka after the lgm and during the holocene whilst sedimentation ended after 1 3 ka the wadi selloum might be characterised by enhanced flooding during humid phases pedogenesis may be used as environmental indicator for more humid climate conditions during mis 3 palaeo calcisol the early holocene calcisol and the late holocene fluvisol this study thus provides first insights into the palaeoenvironmental changes around the rock shelter of ifri n ammar during the last glacial interglacial cycle

palaeoglaciology of an ice sheet through a glacial cycle the european ice sheet through the weichselian abstract satellite images provide unique means of identifying large scale flow generated lineations produced by former ice sheets they can be interpreted to reconstruct the major elements which make up the integrated large scale structure of ice sheets ice divides ice streams interstream ridges ice shelves calving bays the evolving palaeoglaciological structure of the european ice sheet during its decay from the last glacial maximum lgm is reconstructed by reference to these components and in the context of a new map showing isochrons of retreat during the retreat phase in particular the time dependent dynamic evolution of the ice sheet and the pattern of ice stream development are reconstructed crossing lineations are widespread the older ones are suggested to have formed during molten bed phases of ice sheet growth and preserved by frozen bed conditions during the glacial maximum particularly in areas which lay during deglaciation beneath ice divides and inter ice stream ridges both areas of slow flow and possibly frozen bed conditions four phases of growth a1 to a4 and five phases of decay r1 to r5 are used to describe the major climatically and dynamically determined stages in the evolution of the ice sheet through the last glacial cycle the growth and decay patterns are quite different and associated with major shifts in the ice divide reflecting growth from the fennoscandian mountains and decay away from marine influenced margins these patterns were determined by the locations of nucleation areas spatial patterns of climate and calving at marine margins the prevalence of streaming within the retreating ice sheet suggests that the mean elevation of the ice sheet was lower than predicted from glaciological models which do not include streaming and that this might reconcile glaciological models and earth rheology models which infer paleao ice sheet thickness by inverting sea level data

holocene stratigraphy and geomorphological evolution of the aegean coastal plains of anatolia abstract three main stages can be distinguished in the sedimentary development and geomorphological formation of the present delta plains on the aegean coast of turkey the early holocene is characterized by post glacial transgression and dependent sedimentation the middle holocene was the period when sea level reached the present level and apart from small fluctuations stopped rising alluviation and deltaic progradation were prevalent during this transition period from marine to terrestrial environments as for the late holocene deltaic progradation slowed down and delta plains were covered by floodplain sediments these characteristics can be observed in the same sequence throughout the aegean coast of turkey

triassic to recent tectonic evolution of a crestal collapse graben above a salt cored anticline in the gluckstadt graben north german basin abstract in this study we investigate faulting above a salt wall in the gluckstadt graben north german basin two supra salt faults are mapped from coast to coast over a distance of 6 9 km based on offshore and onshore seismic data these faults form a ca 2 km wide crestal collapse graben and pierce the seafloor salt wall evolution started in the early late triassic to early jurassic due to regional extension and resulting sub salt faulting the salt wall was eroded following exposure to costal and sub aerial erosion by the regional mid late jurassic to early cretaceous uplift late cretaceous to early paleogene compressional tectonics reactivated the vertical salt movement and shortened the salt wall creating a salt cored anticline with the crestal collapse graben above the supra salt faults were reactivated between the late eocene and middle miocene when the principal horizontal stress orientation changed from a ne sw to a nw se the present day orientation stratigraphic data indicate that these faults moved mainly in the cenozoic several observations strongly suggest that the faults continued developing during the pleistocene until today i the pleistocene unconformity is concave upwards and cut by faults ii growth strata within the marine holocene deposits above the graben imply recent tectonic movements iii onshore high resolution p wave vibroseis data of the south eastern eckernforde bay suggest about 10 m of faulted holocene strata and iv marine seismic data show the faults piercing the seafloor we suggest that the recent salt tectonics and upward propagation of supra salt faults resulted from differential ice sheet loading that effect on the salt wall stopped once ice grew over the whole structure at which time the wall subsided because of ice loading the salt wall and faults were reactivated again once the ice front retreated so that the ice loaded only one side of the structure

growth patterns of the acheloos and evinos deltas western greece abstract the coastal plain complex on the north side of the gulf of patras has been built by the overlapping acheloos and small evinos deltas upstream river channels are braided on the lower part of the delta they are meandering classical writings indicate that the present acheloos channel has been occupied for at least 2300 years air photographs show three former major distributary channels the present annual sediment discharge suspended 3 4 million tons bedload 2 million tons is sufficient to build all the modern delta plain by progradation of these four distributaries in the last 5000 7000 years of relatively stable sea level old maps and air photographs show that river mouths prograde by periodic plugging of sub distributaries within 1 km of the mouth where the river progrades into deep water 20 m a steep sandy pro delta slope forms and a shoal mouth bar is developed by wave reworking the freshwater muddy plume of the acheloos extends up to 15 km offshore analysis of about 30 bottom samples shows that very silty sediment settles within a few kilometers of the river mouth becoming progressively more clayey offshore marine reworking of abandoned distributaries takes place rapidly 0 5 km in the first ten years and a further 0 5 km in the next 30 years sand is redistributed to form parallel accretionary spits and barrier beaches a shallow pro delta platform up to 2 km wide has formed by such reworking along the southern margin of both deltas gradual subsidence less than 0 5 mm year leads to flooding of shallow lagoons behind barrier beach systems subaerial delta facies have been mapped in the field and extensively sampled in artificial channel cuts normal tidal range is only 16 cm but storm tides up to 1 m high flood low supratidal flats that locally extend several kilometres inland broad immediately subtidal silt flats are found on the inner part of the western evinos pro delta platform silt is drifted in suspension by strong winter easterly winds from the evinos mouth and the pro delta platform is sufficiently wide and shallow to damp down most large waves that would subsequently remove the silt where sand supply is limited the coastline is marked by a sandy low tide terrace and a berm or storm ridge built of variable proportions of sand and reeds only near delta mouths is sand supply sufficient for broad barrier beach dune systems to form

a geochemical and sedimentological perspective of the life cycle of neapolis harbor naples southern italy since the discovery of the ancient harbor of naples in 2004 during construction work on an underground railway geoarchaeological studies undertaken on the archaeological excavation have revealed the main stratigraphic and paleo environmental levels of the harbor site near the piazza municipio however knowledge of the dynamics and paleoenvironmental changes in the water column of the harbor as well as the processes of transport and deposition of sediments that led to siltation and infilling of the harbor basin has been lacking due to the absence of high resolution data to fill these gaps we have undertaken a threedimensional study longitudinal transverse and vertical of the harbor deposits by carrying out geochemical and sedimentological analyses of four stratigraphic sections of the archaeological excavation the results show that after a phase of relative calm during the first half of the 1st c ad siltation of the harbor progressed exponentially up to the 5th c ad when dredging operations were carried out to obtain a water level sufficient for the development of maritime and harbor activities we attribute this acceleration of siltation to a combination of climatic anthropic and volcanic factors volcanic activity was responsible for a high energy tsunami type event during the eruption of vesuvius in 79 ad from the 5th c ad onwards the harbor basin of neapolis does not appear to have been functional as evidenced by its transformation into a lagoon following coastal progradation the last stage of infilling was the development of a flood dominated fan delta under the combined influences of climatic cooling in the early medieval cool period and agro pastoral activities in the catchment area of the harbor several generations of paleo channels containing flash flood deposits as well as sheet wash from sheet floods are indicative of high environmental instability in this period

fennoscandian palaeoglaciology reconstructed using a glacial geological inversion model the evolution of ice sheet configuration and flow pattern in fennoscandia through the last glacial cycle was reconstructed using a glacial geological inversion model i e a theoretical model that formalises the procedure of using the landform record to reconstruct ice sheets the model uses mapped flow traces and deglacial melt water landforms as well as relative chronologies derived from cross cutting striae and till lineations as input data flow trace systems were classified into four types i time transgressive wet bed deglacial fans ii time transgressive frozen bed deglacial fans iii surge fans and iv synchronous non deglacial event fans using relative chronologies and aggregation of fans into glaciologically plausible patterns a series of ice sheet configurations at different time slices was erected a chronology was constructed through correlation with dated stratigraphical records and proxy data reflecting global ice volume geological evidence exists for several discrete ice sheet configurations centred over the scandinavian mountain range during the early weichselian the build up of the main weichselian fennoscandian ice sheet started at approximately 70 ka and our results indicate that it was characterised by an ice sheet with a centre of mass located over southern norway this configuration had a flow pattern which is poorly reproduced by current numerical models of the fennoscandian ice sheet at the last glacial maximum the main ice divide was located overthe gulf of bothnia a major bend in the ice divide was caused by outflow of ice to the northwest over the lowest part of the scandinavian mountain chain widespread areas of preserved pre late weichselian landscapes indicate that the ice sheet had a frozen bed core area which was only partly diminished in size by inward transgressive wet bed zones during the decay phase

sedimentary and tectonic architecture of a large push moraine a case study from hagafellsjokull eystri iceland original article can be found at http www sciencedirect com science journal 00370738 copyright elsevier b v full text of this article is not available in the uhra

harbor areas at ancient troy sedimentology and geomorphology complement homer s iliad for at least two thousand years scholars have debated the location of troy and the events and geographic features described in homer s iliad geologic evidence is used to present a series of maps of the trojan plain that show the geomorphic changes over the past six millennia the geologic evidence correlates very well with the relevant homeric geography

the 1890 surge end moraine at eyjabakkajokull iceland a re assessment of a classic glaciotectonic locality abstract the glaciotectonic architecture and sequential evolution of the eyjabakkajokull 1890 surge end moraines in iceland were studied for understanding better the formation and evolution of glaciotectonic end moraines and their relation to glacier dynamics based on morphological geological and geophysical data from terrain cross profiles cross sections and ground penetrating radar profiles we demonstrate that three different qualitative and conceptual models are required to explain the genesis of the eyjabakkajokull moraines firstly a narrow single crested moraine ridge at the distal end of a marginal sediment wedge formed in response to decoupling of the subglacial sediment from the bedrock and associated downglacier sediment transport secondly large lobate end moraine ridges with multiple closely spaced narrow asymmetric crests formed by proglacial piggy back thrusting thirdly a new model shows that moraine ridges with different morphologies may reflect different members of an end moraine continuum this is true for the eastern and western parts of the eyjabakkajokull moraines as they show similar morphological and structural styles which developed to different degrees the former represents an intermediate member with decollement at 4 5 m depth and 27 33 shortening through multiple open anticlines that are reflected as moderately spaced symmetric crests on the surface the latter represents an end member with decollement at about 27 m depth and 39 horizontal shortening through multiple high amplitude overturned and overthrusted anticlines appearing as broadly spaced symmetric crests we propose that the opposite end member would be a moraine of multiple symmetric wide open anticlinal crests of low amplitude our data suggest that the glacier coupled to the foreland to initiate the end moraine formation when it had surged to within 70 190 m of its terminal position this indicates a time frame of 2 6 days for the formation of the end moraines

late quaternary tectonic and sedimentary history of outer izmir and candarli bays western turkey abstract air gun and 3 5 khz seismic profiles from the eastern aegean sea off turkey show that the continental shelf of outer izmir and candarli bays is formed by several superimposed deltaic sequences during times of lowered sea level associated with late quaternary glaciations deltas prograded seaward more than 60 km from their present positions foreset progradation ceased with the rise of sea level in interglacial and post glacial times and deltas were reestablished far inland in drowned river valleys these major transgressions resulted in unconformities within the superimposed prograded delta sequences the most recent three unconformities are correlated with the beginning of oxygen isotope stages 5 3 and 1 and provide chronostratigraphic markers for a detailed analysis of sedimentation patterns in the late quaternary the coastal shelf and basins are subsiding at an average rate of about 1 m per 1000 years this tectonic subsidence manifests itself as widespread normal block faulting which can be related to the pre miocene structural framework of the region

multi proxy geoarchaeological study redefines understanding of the paleocoastlines and ancient harbours of liman tepe iskele turkey determining the position of liman tepe s ancient clazomenae archaeological features relative to the coastline is important for understanding their intended function and reconstructing the character of aegean maritime activities and sea based trade previous attempts at reconstructing harbour locations at liman tepe relied on extrapolating paleoenvironments based on modern surface topography in light of this samples from a sediment coring survey and terrestrial and underwater archaeological excavations were analysed using multi proxy geoarchaeological methods to determine paleoenvironmental facies micropaleontological foraminifera sedimentological grain size analysis and geochemical d 13 c d 18 o analyses resulted in the reconstruction of the coastal paleogeomorphology including the presence and absence of ancient harbouring areas neither of the previous coastal reconstructions was supported by the new results instead two separate harbouring areas were recognized one coincident with the early bronze age 4800 3900 years bp and a second during the archaic and classical periods c 2800 2400 years bp these results emphasize the necessity for multi proxy geoarchaeological studies when approaching coastal archaeological sites as a means to reconstruct paleocoastal geomorphology and understand ancient maritime development better