the december 2002 july 2003 effusive event at stromboli volcano italy insights into the shallow plumbing system by petrochemical studies abstract on 28 december 2002 the persistent strombolian activity at stromboli was interrupted by the sudden onset of lava emission onto the sciara del fuoco slope a horseshoe shaped depression on the nw flank of the volcano the effusive episode went on until 22 july 2003 and produced a cumulative volume of lavas of 11 106 m3 ranking the event as the largest occurred in the past 30 years the eruptive vents were mainly located in the ne sector of the sciara del fuoco depression at an elevation of 550 600 m a s l on 30 december the eastern portion of the sciara del fuoco collapsed producing a tsunamigenic landslide on 5 april 2003 a paroxysmal eruption occurred at the summit craters during which crystal poor pumiceous products were emitted the paroxysm did not interrupt the lava emission the strombolian activity at the summit craters gradually resumed starting from march 2003 and fully recovered by the end of july periodic sampling of the lava at the active vents was carried out during the entire effusive event all the analysed samples are shoshonitic basalts sio2 48 5 50 4 wt k2o 2 1 2 4 wt in the range of composition observed in the products erupted during the past 20 years they bear about 50 vol zoned crystals of plagioclase an90 60 diopside augite and olivine fo70 73 in a compositionally homogeneous shoshonitic groundmass bulk rock major and trace element contents measured with different methodologies at different laboratories show only minor variations sr and nd isotope ratios are close to those of the crystal rich scoriae erupted in the previous years despite of small compositional variations related to the emptying of the zoned topmost portion of the conduit the data show that the switch from strombolian explosive to effusive activity is not associated with changes of the textures and composition of the erupted products slight but somehow systematic variation of trace elements and isotope ratios between products erupted before and after the 5 april eruption are likely accounted by limited mixing between the fresh volatile rich crystal poor magma erupted as pumice during the paroxysm and the volatile poor crystal rich magma feeding the lava flow the uniform composition of the erupted lava indicates the presence of a large volume of well mixed crystal rich homogeneous magma residing in the shallow plumbing system of the volcano two possible trigger mechanism of the effusive event are here proposed i a discrete input of fresh magma into the lower part of the shallow magmatic system occurred some months before the eruption and was followed by crystallisation degassing and mixing with the crystal rich shallow magma which re homogenised the system these processes eventually led to the rise of the magma at a higher level and failure of the conduit walls ii the onset of the effusion may represent the consequence of a gradual rise of the magma level in the conduits occurred in the past two decades the process of progressive refilling initiated after the 1985 effusive eruption ultimately culminated on 28 december 2002 with the failure of the conduit wall and the opening of vents 100 150 m below the summit craters

late pleistocene and holocene subtropical vegetation dynamics recorded in perched lake deposits on fraser island queensland australia abstract the dune system of fraser island in subtropical queensland australia contains numerous perched lakes with organic rich sediments these lakes are located in the subtropics and their water levels are strongly influenced by precipitation the lakes act as natural rainfall gauges which make them highly sensitive to environmental change paleoecological and paleoclimatological investigations are performed on sediment cores from lake allom a small perched lake on central fraser island a detailed chronology is based on a series of closely spaced ams radiocarbon dates supplemented with sedimentological information based on extrapolation the chronology indicates an age range from 56 14c kyr bp to present with a major hiatus occurring during the last glacial maximum pollen analysis of the lake allom sediment record reveals strong changes between rainforest and open woodland vegetation the holocene portion of the record shows a stepwise vegetation development from dry conditions in the early holocene to high lake levels and increasing forest between 5 5 and 3 cal kyr bp at 3 2 cal kyr bp a large diversification occurred towards the present day heterogeneous sub tropical rainforest vegetation followed by a small rainforest decline at 0 45 cal kyr bp additionally charcoal analysis indicates increases in fire occurrence contemporaneously with periods of drier vegetation and or low lake levels part of the reconstructed vegetation changes can be related to local and regional factors including forest succession dune formation sea level rise and human impact comparison with paleoclimate records from tropical and temperate regions indicates that the temporal and spatial dynamics of vegetation changes in eastern australia are primarily controlled by climate variability particularly the increasing activity of the el nino southern oscillation enso during the late holocene caused greater climate variability in eastern australia resulting in more heterogenous vegetation cover

conceptual models of the evolution of transgressive dune field systems abstract this paper examines the evolutionary paths of some transgressive dune fields that have formed on different coasts of the world and presents some initial conceptual models of system dynamics for transgressive dune sheets and dune fields various evolutionary pathways are conceptualized based on a visual examination of dune fields from around the world on coasts with high sediment supply dune sheets and dune fields tend to accumulate as large scale barrier systems with little colonization of vegetation in arid hyper to arid climate regimes and as multiple active discrete phases of dune field and deflation plain couplets in temperate to tropical environments active dune fields tend to be singular entities on coasts with low to moderate sediment supply landscape complexity and vegetation richness and diversity increases as dune fields evolve from simple active sheets and dunes to single and multiple deflation plains and basins precipitation ridges nebkha fields and a host of other dune types associated with vegetation e g trailing ridges slacks remnant knobs gegenwalle ridges and dune track ridges tree islands and bush pockets three principal scenarios of transgressive dune sheet and dune field development are discussed including dune sheets or dune fields evolving directly from the backshore development following foredune and or dune field erosion and development from the breakdown or merging of parabolic dunes various stages of evolution are outlined for each scenario knowledge of evolutionary patterns and stages in coastal dune fields is very limited and caution is urged in attempts to reverse change and or modify dune fields to restore some perceived loss of ecosystem or dune functioning

offshore killer whale tracking using multiple hydrophone arrays to study delphinid near surface movements and behavior two l shaped hydrophone arrays and one vertical hydrophone line array were deployed at shallow depths 125 m from the floating instrument platform r p flip moored northwest of san clemente island in the southern california bight a three dimensional propagation model based passive acoustic tracking method was developed and used to track a group of five offshore killer whales orcinus orca using their emitted clicks in addition killer whale pulsed calls and high frequency modulated hfm signals were localized using other standard techniques based on these tracks sound source levels for the killer whales were estimated the peak to peak source levels for echolocation clicks vary between 170 205 db re 1 pa 1 m for hfm calls between 185 193 db re 1 pa 1 m and for pulsed calls between 146 158 db re 1 pa 1 m

post glacial sea level rise from a coral record at huon peninsula papua new guinea dating of coral reef terraces can provide a record of changes in sea level which should be pronounced during the transition between glacial and interglacial periods cores drilled from coral reefs at barbados in the equatorial west atlantic1have revealed the sea level changes that occurred during the younger dry as event at the end of the last glacial maximum 11 000 yr bp it has not been known however whether pacific coral reefs can grow at a rate sufficient to keep up with the rise in sea level during such a transition here we report results obtained from a 52 m drill core from the post glacial reef at huon peninsula papua new guinea spanning the interval from 7 000 to 11 000 14c yr bp which show that coral growth kept pace while the relative sea level rose by 50m although the tectonic environment is very different from that at barbados the two records compare well when corrections are made for local tectonic uplift showing that sea level rise was similar at both locations the rate of rise was greatest between 9 000 and 10 00014c yr bp corresponding to the time of the younger dryas

dating the cooloola coastal dunes of south eastern queensland australia abstract the cooloola sand dunes are part of a series of aeolian parabolic dunes that stretch along the east coast of australia they form a chronosequence showing increasing weathering soil formation and water erosion across six geomorphically recognized soil landscapes these landscapes were recognized from air photographs and further refined on the basis of some 150 auger holes across the dunes data about the structure and floristics of the vegetation were collected at the same time there is a significant body of literature about the cooloola dunes but there are two areas that have not been satisfactorily considered first the previous dating which gave inconsistent results has been superseded by single grain osl dates and second cooloola has not been considered in a regional context here we report the results of single grain optically stimulated luminescence osl analyses for 31 samples for 21 sites across the geomorphic landscapes the sites were selected near the apex of each dune as this represents the last depositional date and the least disturbed by sand movement we recognized 10 units across the dunes on the basis of the dates available the dune ages ranged from recent to 725 ka the largest dunes at some 320 m high were dated at around 140 ka and these dunes carry the maximum vegetation biomass of this dunefield beyond this vegetation maximum the dunes had lost their parabolic shape due to prolonged weathering and erosion and the vegetation is greatly reduced in height and biomass the depth to the soil b horizon gradually deepens with age to form giant podzols in the older dunes the depth to the b horizon was remarkably consistent within the geomorphic landscapes across the length and breadth of the dunes these studies place the cooloola dunes in a unique position as the chronosequence is intact the possible processes that lead to the formation of the dunes and the regional implications are discussed secondly it shows the buildup and decline of the dune ecosystems and acts as a model for all ecosystems forest succession models which place less emphasis on soil development miss this important process

biogeomorphic model of dunefield activation and stabilization on the northern great plains abstract a conceptual model is proposed for the activity of sand dune systems on the northern great plains that incorporates vegetation growth theory and geomorphic system theory dunefield activity is modeled as a cyclic phenomenon alternating between active and stable states with the latter as the system state attractor the model is divided into two constituent parts an activation model and a stabilization model the activation model is qualitative and describes the transition from stable to active dunes as the result of a climatic perturbation such as drought that decreases vegetation cover the intensity and duration of the climatic perturbation determines the rate of decline of vegetation cover the stabilization model is quantitative and describes the transition from active to stable dunes using a logistic model of vegetation growth small perturbations during stabilization can prolong the duration of recovery enabling dunes to remain active well after the initial perturbation despite the geographic focus of this study the model appears applicable to a variety of environments where dune activity is limited in part by vegetation cover

understanding late quaternary change at the land ocean interface a synthesis of the evolution of the wilderness coastline south africa coastal barrier systems have been widely used to understand the responses of coastal margins to fluctuating pleistocene sea levels what has become apparent particularly with the development of robust chronological frameworks is that gaps in terrestrial barrier sedimentary records are not uncommon and that they most likely reflect phases of barrier construction on the now submerged continental shelf thus understanding the land ocean interface through time is critical to fully appreciate the quaternary archives contained within the barriers and their associated back barrier deposits this study uses offshore and lakefloor back barrier seismic profiling from the south african south coast at wilderness to link the sub aerially exposed barrier stratigraphy to the currently submerged geological and sedimentological record a total of eight separate submerged aeolian units are identified at water depths of up to 130 m below mean sea level their approximate ages are constrained with reference to the eustatic sea level record and the deepest units are consistent with the estimated magnitude of sea level lowering during the last glacial maximum lgm on the south african coastline as previously assumed aeolian sedimentation tracked the shoreline onto the continental shelf during the late pleistocene during sea level regressions both the incision of fluvial channels and the deposition of back barrier systems occurred across the continental shelf during late low stand early transgression periods landward shoreface migration occurred pre existing channel incisions were infilled and pre existing barriers were truncated rapid transgression however allowed the preservation of some back barrier deposits possibly aided by protection from antecedent topography as sea level neared the present day elevation erosion of the mid shelf sediments resulted in the development of a holocene sediment wedge which was augmented by holocene fluvial sediment supply the holocene sand wedge is preserved in the back barrier lakes and was deposited during the holocene highstand inundation overlying middle to late holocene terrestrial muds reflect the deposition of river borne mud onto the shelf these results clearly demonstrate that within transgressive regressive sea level cycles accommodation space for barriers is controlled by antecedent drainage systems and gradients on the adjacent inner continental shelf

persistent solar influence on north atlantic climate during the holocene surface winds and surface ocean hydrography in the subpolar north atlantic appear to have been influenced by variations in solar output through the entire holocene the evidence comes from a close correlation between inferred changes in production rates of the cosmogenic nuclides carbon 14 and beryllium 10 and centennial to millennial time scale changes in proxies of drift ice measured in deep sea sediment cores a solar forcing mechanism therefore may underlie at least the holocene segment of the north atlantic9s 1500 year cycle the surface hydrographic changes may have affected production of north atlantic deep water potentially providing an additional mechanism for amplifying the solar signals and transmitting them globally

theoretical constraints and chronological evidence of holocene coastal development in central and southern new south wales australia abstract holocene coastal evolution in new south wales has been interpreted essentially as the unfolding of the impact of marine transgression sea level on this coast supposedly reached its present height at 6 6 5 ka and varied

evolution and environmental impacts of the eruption of laacher see volcano germany 12 900 a bp abstract laacher see volcano lsv 40 km south of bonn explosively erupted ca 6 3 km 3 of chemically strongly zoned phonolite magma probably during spring 12 900 years ago the resulting eruption column having reached at least 20 km in height the bulk of the laacher see tephra lst was deposited east of the volcano within the neuwied basin lst ashes form the most important stratigraphic marker in lateglacial deposits over much of central europe a minimum of 2 mt total s was calculated to have been released during the eruption by comparing pre and posteruptive volatile concentrations in glass inclusions and pumice matrix glasses because a separate s bearing vapor phase was probably present in the magma prior to eruption as indicated by the high melt h 2 o contents close to saturation level the actual amount of s released during the eruption could have significantly exceeded 2 mt the sulfuric acid aerosol layer resulting from the massive stratospheric s input probably resided in the stratosphere for years and most likely had a significant impact on climate and thus the environment increased precipitation in central europe and or impairment of the vegetation cover for several years is suggested by several proxies especially increased sediment supply into lakes proximal to the eruptive center major environmental impacts include an initial blast that felled trees up to 4 km away from vent fast deposition of huge tephra volumes led to the complete disruption of rhine river within the lower neuwied basin and the damming up of a lake ca 140 km 2 in areal extent sudden collapse of the temporary tephra dam caused a catastrophic flood wave downstream whose deposits are recognized as far north as bonn reworking of unconsolidated tephra deposits over several 100 km 2 was widespread and extensive generating abundant lahars and flood plain deposits a braided river system established in neuwied basin probably persisted up to several years recent reports for a second eruption of lsv are not confirmed

effective beam pattern of the blainville s beaked whale mesoplodon densirostris and implications for passive acoustic monitoring the presence of beaked whales in mass strandings coincident with navy maneuvers has prompted the development of methods to detect these cryptic animals blainville s beaked whales mesoplodon densirostris produce distinctive echolocation clicks during long foraging dives making passive acoustic detection a possibility however performance of passive acoustic monitoring depends upon the source level beam pattern and clicking behavior of the whales in this study clicks recorded from digital acoustic tags dtags attached to four m densirostris were linked to simultaneous recordings from an 82 hydrophone bottom mounted array to derive the source level and beam pattern of the clicks as steps towards estimating their detectability the mean estimated on axis apparent source level for the four whales was 201 dbrms97 the mean 3 db beamwidth and directivity index estimated from sequences of clicks directed towards the far field hydrophones were 13 and 23 db respectively while searching for prey blainville s beaked whales scan their heads horizontally at a mean rate of 3 6 s over an angular range of some 10 thus while the di indicates a narrow beam the area of ensonification over a complete foraging dive is large given the combined effects of body and head movements associated with foraging

last glacial coastal dunes in eastern australia and implications for landscape stability during the last glacial maximum abstract the last glacial maximum or lgm 25 000 15 000 yr b p has been recognized in australia as a period of increased dryness coolness continentality and windiness compared to earlier and later period enhanced aeolian activity during the lgm occurred in arid and semi arid regions of western central and eastern australia the east coast has been considered to have been better watered and vegetated however at a number of sites from tasmania to north queensland there is evidence for extensive aeolian instability of coastal sand deposits dating by radiocarbon and thermoluminiscence techniques has supported morphologic and stratigraphic evidence of dune formation during the lgm under the influence of westerly offshore winds in the southern sector of the east coast i e south of 31 s latitude and southeast winds to the north it is now apparent that vegetation cover on sandy surfaces was quite patchy during the lgm sand surface instability under conditions of strong west or southeast winds promoted linear and or parabolic dune development this suggests greater concentration of forests in more discrete protected sites along the eastern escarpment than was previously considered by palaeoecologists more widespread drier and cooler climatic conditions operated even in coastal regions on expanded continental shelves at this time stabilization of areas of active dunes became more likely as sea levels rose reduced windiness occurred and precipitation increased as sea surface temperatures began to rise in the holocene

eolian depositional episodes controlled by late quaternary relative sea level changes on the imbituba laguna coast southern brazil the late quaternary coastal eolian deposits of the imbituba laguna region santa catarina state southern brazil comprise two eolian depositional sequences separated by an unconformity the older eolian sequence a is correlated to the relative sea level rise of the last interglacial period the eolian sequence b was initiated during the relative sea level rise in the post glacial period and extends up to active dunefields the correspondence between the two eolian depositional episodes represented by these sequences and the relative sea level highstand phases is confirmed by thermoluminescence and optically stimulated luminescence dating this correspondence is explained by a conceptual model that links the availability of coastal sediments for eolian transport with relative sea level changes the link between relative sea level changes and coastal eolian sedimentation can be used to integrate coastal eolian systems to the sequence stratigraphy model

three dimensional tracking of cuvier s beaked whales echolocation sounds using nested hydrophone arrays cuvier s beaked whales ziphius cavirostris were tracked using two volumetric small aperture 1 m element spacing hydrophone arrays embedded into a large aperture 1 km element spacing seafloor hydrophone array of five nodes this array design can reduce the minimum number of nodes that are needed to record the arrival of a strongly directional echolocation sound from 5 to 2 while providing enough time differences of arrivals for a three dimensional localization without depending on any additional information such as multipath arrivals to illustrate the capabilities of this technique six encounters of up to three cuvier s beaked whales were tracked over a two month recording period within an area of 20 km 2 in the southern california bight encounter periods ranged from 11 min to 33 min cuvier s beaked whales were found to reduce the time interval between echolocation clicks while alternating between two inter click interval regimes during their descent towards the seafloor maximum peak to peak source levels of 179 and 224 db re 1 pa 1 m were estimated for buzz sounds and on axis echolocation clicks directivity index 30 db respectively source energy spectra of the on axis clicks show significant frequency components between 70 and 90 khz in addition to their typically noted fm upsweep at 40 60 khz

crystal recycling in the steady state system of the active stromboli volcano a 2 5 ka story inferred from in situ sr isotope and trace element data in situ sr isotope data by microdrilling coupled with major and trace element analyses have been performed on plagioclase and clinopyroxene from seven samples collected during the 2002 2003 eruptive crisis at stromboli volcano aeolian islands italy on 28 december 2002 the persistent moderate explosive activity was broken by an effusive event lasting about 7 months a more violent explosion paroxysm occurred on 5 april 2003 two magma types were erupted namely a volatile poor and highly porphyritic magma hp magma poured out as scoria or lava and a volatile rich phenocryst poor magma lp magma found as pumice lp magma differs from the hp magma also for its slightly less evolved chemistry the groundmass composition and the lower sr isotope ratios micro sr isotope data show the presence of zoned minerals in strong isotope disequilibrium as previously found in products erupted in 1984 1985 and 1996 ad with 87sr 86sr values generally decreasing from cores to rims of minerals only some outer rims testify for equilibrium with the host groundmass the internal mineral zones with high sr isotope ratios 0 70665 0 70618 are interpreted as antecrysts crystallised during the previous activity and recycled in the present day system since the opening shoshonitic activity of the recent period which occurred at about 2 5 ka ago this result has implications for the dynamics of the present day plumbing system of stromboli at intermediate pressure about 2 3 km depth and allows us to propose a model whereby an hp magma reservoir is directly interconnected at the bottom with a cumulate crystal much reservoir efficient mixing between residing hp and input lp magmas can occur in this reservoir due to more similar rheological characteristics of the two magmas than in the conduit where crystallisation is enhanced by degassing antecrysts and possibly melts re enter in the hp magma reservoir both from the bottom recycled by ascending lp magmas crossing the crystal mush and from the top recycled by descending degassed and dense hp magma residual of the periodic strombolian explosions at the surface the isotope variation measured in the groundmasses allows calculating the proportion of the lp magma entering the shallow hp magma reservoir at 20 from this proportion we estimate that the total volume of lp magma input during 2002 2003 closely matches the magma volume erupted in the effusive event suggesting a steady state system at broadly constant volume the comparison with estimates of the lp magma volume ejected by the paroxysm indicates that the lp magma amount directly reaching the surface during the 5 april paroxysm is minimal with respect to that entering the system

when magmas do not interact paired roman age activity revealed by tephra studies at stromboli volcano detailed stratigraphic and geochemical studies were carried out on remnants of the partially collapsed pizzo o sopra la fossa pizzo scoria cone which represents the best viewpoint for observing the present day activity on top of the stromboli volcano italy the main outcrop is above the active craters and is strongly altered by acid fumarolic gases for this reason the pizzo activity has previously been poorly studied for age and composition we focus mainly on the well preserved le croci fallout succession we show that the pizzo activity occurred in the roman age 2 4 1 8 ka and was fed by two compositionally and genetically distinct magma groups each occupying a separate reservoir shoshonitic basalts pizzo sho were stored at lower depths than high k basalts to high k basaltic andesites pizzo hkca although pizzo sho and pizzo hkca magmas were affected by multiple mafic magma inputs with different dynamics as reflected in variable mineral zoning they did not interact with each other they were however erupted simultaneously suggesting they were emitted by two unconnected conduits and vents located in the summit area stromboli historic activity was thus quite different from present day activity in the roman age the volcano was characterised by paired activity taking place on the summit with similar explosive characteristics from two coeval vents each fed by different and non parental magmas while the pizzo sho magmas still persist in the present day shallow reservoir the pizzo hkca magmas could be quiescent and re activated in the future possibly from an eccentric vent fissure

onset of the persistent activity at stromboli volcano italy stromboli known worldwide as the lighthouse of the mediterranean is commonly believed to have been in a state of persistent activity for the past 2000 2500 years however historical sources older than 1000 a d are not accurate enough to assess if the activity of the volcano was exactly the same as we see at present in order to attempt to identify the onset of the present eruptive regime and assess if it has been maintained with the same characteristics through time stratigraphic and radiometric studies of the recent tephra deposits were undertaken up to 4 m deep stratigraphic trenches dug at a height of approximately 500 m on the ne flank of the volcano exposed a conformable tephra pile containing charcoal fragments one of the most interesting finds was the discovery of a 7 cm thick weathered bed rich in organic matter thin palaeosol approximately 3 m below the surface the sequence underneath the palaeosol consists of decimetre thick lapilli fallout beds alternating with ash deposits bearing small charcoals with calibrated ages of between the fourth century b c and the first century a d the sequence above the palaeosol is charcoal free and consists of coarse ash deposits with discrete centimetre thick lapilli fallout beds composed of crystal poor golden pumice and subordinate crystal rich black scoriae similar to scoria pumice pairs emitted during the more energetic explosions of the present day activity the data collected indicate that between the third and seventh centuries a d after a period of quiescence the activity resumed with an eruptive style identical to the present one we conclude that the lighthouse of the mediterranean actually began its activity in a period much later than previously thought

warmer or cooler late holocene marine palaeoenvironments interpreting southeast australian and brazilian sea level changes using fixed biological indicators and their δ18o composition abstract relic inter tidal assemblages of sessile organisms which are referred to as fixed biological indicators fbis are shown to be useful proxies for late holocene climatic and environmental changes as well as direct indicators of short term fluctuations in sea level a detailed comparison of change in the inter tidal assemblages of two southern hemisphere sites at comparable latitudes port hacking new south wales south east australia and the laguna imbituba region of southern brazil indicates periods of marked similarities in the timing and nature of changes at 5200 3800 cal years bp and differences after 2400 cal years bp there is sufficient concurrence of cooling phases and falling sea levels to strongly suggest that in some cases global rather than regional forcing factors are at work the value of inter tidal organisms as indicators of changed environments is developed by identifying the past and present distributions of the common marker species tubeworms barnacles and mussels the 18 o content of these extant specimens at port hacking confirmed changes in ocean water temperature and associated sea level behaviour corresponding to invasion or extinction of temperature sensitive species a similar pattern is repeated although in a less marked fashion in the laguna imbituba region of southern brazil

foredunes and blowouts initiation geomorphology and dynamics this paper reviews the initiation dynamics geomorphology and evolution of incipient foredunes established foredunes and blowouts incipient foredunes may be initiated in a variety of ways leading to the formation of ramps terraces or ridges depending on progradation rates vegetation type and cover sediment transport rates and scale of erosional processes vegetation cover morphology growth rates and types combine with aerodynamic processes to determine dune and swale morphology established foredunes are classified into five morpho ecological types and the flow behaviour over two types is detailed a new model of foredune evolutionary paths at various possible time scales is presented blowout initiation dynamics and sediment transport and evolution is examined throughout the review the gaps in present understanding of dune processes and a range of ideas for new research possibilities are provided

aeolianite and barrier dune construction spanning the last two glacial interglacial cycles from the southern cape coast south africa the southern cape region of south africa has extensive coastal aeolianites and barrier dunes whilst previously reported limited knowledge of their age has precluded an understanding of their relationship with the climatic and sea level fluctuations that have taken place during the late quaternary sedimentological and geomorphological studies combined with an optical dating programme reveal aeolianite development and barrier dune construction spanning at least the last two glacial interglacial cycles aeolianite deposition has occurred on the southern cape coast at ca 67 80 88 90 104 128 160 189 and 200 ka before the present using this and other published data coupled with a better understanding of late quaternary sea level fluctuations and palaeocoastline configurations it is concluded that these depositional phases appear to be controlled by interglacial and subsequent interstadial sea level high stands these marine transgressions and regressions allowed onshore carbonate rich sediment movement and subsequent aeolian reworking to occur at similar points in the landscape on a number of occasions the lack of carbonates in more recent dunes oxygen isotope stages 1 2 and 4 5 is attributed not to leaching but to changes to carbonate production in the sediment source area caused by increased terrigenous material and or changes in the balance between the warm agulhas and nutrient rich benguela ocean currents

tracking dolphin whistles using an autonomous acoustic recorder array dolphins are known to produce nearly omnidirectional whistles that can propagate several kilometers allowing these sounds to be localized and tracked using acoustic arrays during the fall of 2007 a km scale array of four autonomous acoustic recorders was deployed offshore of southern california in a known dolphin habitat at 800 m depth concurrently with the one month recording a fixed point marine mammal visual survey was conducted from a moored research platform in the center of the array providing daytime species and behavior visual confirmation the recordings showed three main types of dolphin acoustic activity during distinct times primarily whistling during daytime whistling and clicking during early night and primarily clicking during late night tracks from periods of daytime whistling typically were tightly grouped and traveled at a moderate rate in one example with visual observations traveling common dolphins delphinus sp were tracked for about 10 km with an average speed of 2 5

hydro isostasy and the sea level isobase of 5500 b p in north queensland australia abstract previous studies of holocene sea level in north queensland have been based on a variety of sea level related deposits with interpretations of mid holocene levels ranging from near zero up to 4 m above present we report data from 8 carefully controlled new sites located from the palm group northwards and extending into the gulf of carpentaria field evidence is from coral reef flats and prograded coastal deposits the highest sea level on inner shelf islands and mainland coast occurred 5500 yrs ago the results of this and of certain previous studies are reduced to a common reference surface or isobase which varies systematically in elevation across the region the isobase correlates strongly with predicted hydro isostatic deformation caused by postglacial sea level rise

inter tidal fixed indicators of former holocene sea levels in australia a summary of sites and a review of methods and models abstract the reconstruction of mid to late holocene marine environments using the calcareous remains of inter tidal fixed biological indicators as sea level proxies is reviewed useful palaeo environmental information can be obtained from the fossil evidence of successive invasions and disappearances of tropical and temperate species within the sub fossil inter tidal biological sequences examples illustrating spatially synchronous late holocene sea level fluctuations are described from 3000 km of north south coastline along eastern australia the method uses tightly constrained species such as the tubeworm galeolaria caespitosa which allows for the precise measurement of relative sea level fluctuations by using the differential between emerged sub fossil encrustations and current distributions of the same species the error range can be defined according to the extent of preservation of the relic distributions particularly the extent that diagnostic boundaries between species limited to different inter tidal zones have been preserved the rapidity of sea level fluctuations is inferred by the preservation from erosion of emerged shell layers as well as discontinuities in the relic biological sequences and the relative preservation of fragile species this apparent rapidity of sea level fluctuations as well as evidence of near uniform synchronous sea level heights along the north south span of the entire australian coast and equally consistent variations australia wide in spencer gulf and rottnest island raises questions about the predicted poleward decline of sea level curves derived from hydro isostatic rebound modelling

three magmatic components in the 1973 eruption of eldfell volcano iceland evidence from plagioclase crystal size distribution csd and geochemistry abstract the 1973 eruption of eldfell volcano iceland appears to have been a short simple event but textural and geochemical evidence suggest that it may have had three different magmatic components the first erupted fissure magmas were chemically evolved rich in plagioclase 18 and had shallow straight crystal size distribution csd curves the early lavas were less evolved chemically had lower plagioclase contents 13 and steeper slightly concave up csds the late lavas were chemically similar to the early lavas but even richer in plagioclase than the initial magmas 24 and had the steepest csds there was no chemical evidence for plagioclase fractionation but compositional diversity could be produced by clinopyroxene fractionation which must have occurred at depth we propose that the eruption started with old coarsened ostwald ripened magma left over from a previous eruption possibly that which produced surtsey island ten years earlier the early flows may be mixtures of small amounts of this old magma with a new low crystallinity uncoarsened magma or a completely new magma the late flows are another new magma from depth chemically similar to the early flows but which has grown plagioclase under increasing saturation undercooling perhaps during its ascent all three magmatic components may have originated from the same parent but had varying degrees of clinopyroxene fractionation plagioclase nucleation and growth and coarsening

conditions of magma storage degassing and ascent at stromboli new insights into the volcano plumbing system with inferences on the eruptive dynamics stromboli is known for its persistent degassing and rhythmic strombolian activity occasionally punctuated by paroxysmal eruptions the basaltic pumice and scoria emitted during paroxysms and strombolian activity respectively differ in their textures crystal contents and glass matrix compositions which testify to distinct conditions of crystallization degassing and magma ascent we present here an extensive dataset on major elements and volatiles co2 h2o s and cl in olivine hosted melt inclusions and embayments from pyroclasts emplaced during explosive eruptions of variable magnitude magma saturation pressures were assessed from the dissolved amounts of h2 oa nd co2 taking into account the melt composition evolution both pressures and melt inclusion compositions indicate that 1 ca basaltic melts entrapped in high mg olivines fo89 90 generate stromboli basalts through crystal fractionation and 2 the stromboli plumbing system can be imaged as a succession of magma ponding zones connected by dikes the 7 10 km interval where magmas are stored and differentiate is periodically recharged by new magma batches possibly ranging from ca basalts to basalts with a co2 rich gas phase these deep recharges promote the formation of bubbly basalt blobs which are able to intrude the shallow plumbing system 2 4 km where co2 gas fluxing enhances h2o loss crystallization and generation of crystal rich dense degassed magma chlorine partitioning into the h2o co2 bearing gas phase accounts for its efficient degassing 69 under the open system conditions of strombolian activity paroxysms however are generated through predominantly closed system ascent of basaltic magma batches from the deep storage zone in this situation crystallization is negligible and sulfur exsolution starts at 170 mpa chlorine remains dissolved in the melt until lower pressures only 16 being lost upon eruption finally we propose a continuum in explosive eruption energy from strombolian activity to large paroxysmal events ultimately controlled by variable pressurization of the deep feeding system associated with magma and gas recharges

an 800 kyr record of dune emplacement in relationship to high sea level forcing cooloola sand mass queensland australia abstract the cooloola sand mass is a large coastal dune field situated in southeast queensland australia and is part of a much larger system of coastal dune fields including the world s largest sand island fraser island as well as moreton island and stradbroke island cooloola is characterised by a sequence of onlapping parabolic dune units that have been emplaced episodically over the pleistocene and holocene the tectonically stable coastline of se queensland is an ideal area to study the driving mechanisms of coastal dune development as sea level variability is driven primarily by glacial eustasy geomorphic and chronostratigraphic analyses have identified seven major periods of dune activity with the earliest phase of deposition occurring ca 800 ka subsequent periods of dune emplacement date to about ca 150 ka 110 ka 10 6 ka 5 3 5 ka ca 2 ka and 0 4 0 2 ka the holocene dune activity coincides with the last stages of post glacial marine transgression and suggests these large parabolic dunes formed in response to rising sea levels it is likely that this pattern is consistent through the pleistocene and the mis 5 interglacial period is also recorded for earlier events the large absolute errors on the ages make interpretation difficult there is a notable absence of osl ages dating to the last glacial maximum and no ages that are unambiguously associated with lowstand periods this is most likely because the coast would have been 60 km offshore of its current position during lowstands limiting sediment supply and wind energy at the modern coast these results provide strong evidence that coastal dune fields in se australia are predominantly emplaced during sea level rise as originally proposed in the cooper thom model

podzol chronosequences on coastal dunes of eastern australia chronosequences of freely drained podzols formed in extensive dune systems of quartz sands along the east coast of australia offer unique opportunities for comparing temporal changes in different climatic zones during the late quarternary the largest areas and greatest number of dune systems occur along the subtropical coast near brisbane here parts of six dune systems have not been covered by younger deposits and have been exposed to weathering since deposition these areas constitute a relative age sequence on which podzols have formed with solum depths varying with age from 20 m absolute ages for each system have not been determined but differences in erosion and weathering depths and comparisons with dated dunes elsewhere along the coast indicate an age sequence extending back at least to the last interglacial similarities in geomorphology and soils enable correlation with dune systems in other areas to the north and south and so provide a greater potential for examining temporal changes in soils and biological systems than that of previous soil chronosequences1 5

echolocation clicks of free ranging cuvier s beaked whales ziphius cavirostris strandings of beaked whales of the genera ziphius and mesoplodon have been reported to occur in conjunction with naval sonar use detection of the sounds from these elusive whales could reduce the risk of exposure but descriptions of their vocalizations are at best incomplete this paper reports quantitative characteristics of clicks from deep diving cuvier s beaked whales ziphius cavirostris using a unique data set two whales in the ligurian sea were simultaneously tagged with sound and orientation recording tags and the dive tracks were reconstructed allowing for derivation of the range and relative aspect between the clicking whales at depth the whales produced trains of regular echolocation clicks with mean interclick intervals of 0 43 s 0 09 and 0 40 s 0 07 the clicks are frequency modulated pulses with durations of 200 s and center frequencies around 42 khz 10 db bandwidths of 22 khz and q3 db of 4 the sound beam is narrow with an estimated directionality index of more than 25 db

multiple sector collapses at stromboli volcano italy how they work this paper demonstrates that four large sector collapses have affected the nw flank of the stromboli volcano in the past 13 ka alternating with growth phases in order to contribute to the evaluation of the critical conditions which trigger lateral collapses a reconstruction of the geometry of each collapse of the volcano edifice in the four stages that preceded the relative collapse events is also presented and a computation of the landslide volume this reconstruction is based on new field data plotted in three dimensions prior to the initial 13 ka collapse the volcano was 1125 100 m high above sea level the collapse had a volume of 2 23 0 87 km3 whereas the pre collapse volcano volume was 218 8 7 7 km3 the next edifice that failed was 900 70 m high a s l the collapse volume was 1 0 54 km3 with a precollapse volcano volume of 201 4 5 4 km3 the edifice then grew to 1000 60 m a s l the third collapse had a volume of 1 08 0 39 km3 and occurred within a volcano with a volume of 209 1 4 6 km3 this was followed by a new growth phase followed by the last collapse with a volume of 0 73 0 22 km3 the volcano volume was about the same as the present one the present active crater zone is at 780 m a s l in the first three collapses sliding surfaces cut the main magma conduit in the last collapse the upper scarp coincided with the conduit location dyking along a main ne trending weakness zone across the volcano summit exerted a lateral force for collapse inception the decrease of the landslide volumes with the age and the concentric scarps of the four collapses suggest that the younger sliding planes tended to become more superficial and to decrease the areal extent this is interpreted as due to a successively weaker eruptive products from dominantly lavas to dominantly pyroclastics and b the feedback effects between collapses and dykes that injected along the lateral segments of the first collapse slide plane

scanning electron microscope study of zircons and rutiles from a podzol chronosequence at cooloola queensland australia summary a chronosequence of four soils derived from aeolian deposited sand at cooloola along the eastern coast of southern queensland has been studied to document predepositional and pedogenic changes in zircon and rutile grains in the fine sand fraction 53 125 m with increasing soil age the soils range in age from holocene typic quartzipsamment presently drifting sand to mid pleistocene spodic quartzipsamment 90 ka bp parent materials are moderately stratified sands with irregular depositional layers in places having high concentration of heavy mineral grains scanning electron microscopy was used to characterize grain surface microtexture by a semi quantitative method based on frequency of occurrence of ten classes of surface microtextures pedogenic changes were quantified and differences between horizons in the same profile between different profiles within the same horizon and between minerals were tested for significance using the 2 distribution zircon grains are less chemically weathered during pedogenesis than rutile possibly due to the higher iron content of the latter however zircons tend to show more features which can be associated with physical alteration rutile grains in the illuviated b2hs horizons of the troporthod and spodic quartzipsamments are more thickly coated with poorly crystalline iron and alumino silicate compounds compared with zircon grains and the presence of grain coatings does not seem to have prevented the surfaces of grains from developing solution pits with increasing age there is a preponderance of weathering features on grains of both minerals the presence of various shapes and surface microtextures on grains from the different soils suggests a multiple grain source for zircon and rutile and a complex predepositional history for these minerals nevertheless microtextural features of zircons and rutiles are valuable for the interpretation of the extent and nature of post depositional weathering

mafic and ultramafic xenoliths in san bartolo lava field new insights on the ascent and storage of stromboli magmas mafic and ultramafic xenoliths are well represented within a large basaltic lava field of stromboli these basalts known as san bartolo lavas show a high k calc alkaline hkca affinity and were erupted 5 ka bp xenoliths consist of olivin gabbro gabbronorite anorthosite dunite wehrlite and clinopyroxenite thermobarometric estimates for the crystallization of gabbroic materials show minima equilibration pressures of 0 17 0 24 gpa at temperatures ranging from 940 to 1 030 c these materials interacted with hydrous ascending hkca basaltic magmas with temperatures of 1 050 1 100 c at pressures of about 0 2 0 4 gpa these pressure regimes are nearly identical to those found for the crystallization of phenocrystic phases within hkca basaltic lavas gabbroic inclusions are regarded as cumulates and represent crystallized portions of earlier hkca strombolian basalts

new evidence for episodic post glacial sea level rise central great barrier reef australia abstract we present an extensive database of 364 radiocarbon dates from coastal and marine sediments of the central great barrier reef gbr shelf of which 110 are previously unpublished the elevation data have been reduced to a common datum australian height datum ahd and the various sources of error have been assessed using modern lithological and biological relationships with sea level the elements of the radiocarbon database have been converted into sea level indicators the upper bound of the assembled dataset corresponds to a best estimate sea level curve and the full dataset provides a narrow envelope for sea level rise on the gbr shelf for the last 11 12 kyr not including hydro isostatic crustal flexing the envelope is consistent with episodic rise in post glacial sea levels the rising post glacial sea level probably included stillstands or minor falls at ca 45 m ahd at ca 10 5 kyr b p 5 m 7 8 kyr b p 2 m ca 6 kyr b p and 1 7 m 5 5 kyr b p there is evidence for a significant fall in sea level between stillstands at 11 m 8 5 kyr b p and 17 m 8 2 kyr b p stillstand durations apparently ranged between the vertical spread in the derived sea level data is very wide the use of shell material for dating seems unreliable and prone to large and unpredictable errors data from bulk mangrove muds appear reliable for determination of ancient sea level but may at times result in sea level being placed up to 4 m below the true level in situ biogenic carbonates such as preserved oyster beds and coral micro atolls are the most reliable indicators of sea level position while deposits of mangrove mud give a useful first order approximation of ancient sea levels caution should be used in drawing sea level curves from few data points we conclude that the post 11 12 kyr b p relative rise in sea level was episodic on the central gbr continental margin more data are required to define clearly sea level change up to ca 20 m at 9 kyr b p

soil phosphorus fractionation and nutrient dynamics along the cooloola coastal dune chronosequence southern queensland australia abstract the amounts and forms of soil phosphorus p follow predictable patterns during long term pedogenesis but have rarely been examined along subtropical chronosequences we quantified changes in soil nutrient stocks foliar nutrient concentrations and the chemical forms of soil p along the cooloola chronosequence a series of coastal dunes spanning ca 500 000 years of pedogenesis in subtropical queensland the total p stock in the upper 30 cm of the soil profile declined continuously with soil age from 229 237 kg ha 1 on the youngest soils 40 years old to 24 28 kg ha 1 on the oldest soils 195 460 ka in contrast total carbon c and nitrogen n stocks increased initially along the chronosequence and then declined in the oldest soils as a consequence soil n p ratios increased continually throughout the sequence from 4 on the youngest soils to 27 30 on the oldest soils this indication of increasing biological p stress and ultimately p limitation was further supported by a decline in foliar p concentrations and increasing foliar n p ratios of two common plant genera along the chronosequence sequential p fractionation revealed that although all forms of p declined during pedogenesis young soils contained low concentrations of primary mineral p and relatively high concentrations of occluded p associated with secondary minerals suggesting that the parent sand originated from strongly weathered continental soils we conclude that the cooloola chronosequence is an important example of long term ecosystem development under a subtropical climate although the pre weathered nature of the parent sand indicates that the sequence represents a modification of the walker and syers model of p transformations during pedogenesis

volcanological and magmatological evolution of stromboli volcano aeolian islands the roles of fractional crystallization magma mixing crustal contamination and source heterogeneity the present paper reports the results of a detailed stratigraphical petrological and geochemical investigation on the island of stromboli aeolian arc southern tyrrhenian sea major and trace element data determined on a large quantity of samples from well established stratigraphic positions indicate that the magmatological evolution of the island through time was more complex than previously known the activity of the exposed part of stromboli which occurred over a time span of about 100 000 years started with the emission of high k calc alkaline hkca volcanics which were covered by calc alkaline ca shoshonitic sho high k calc alkaline hkca and potassic ks products the most recent activity consists of hkca lavas and the present day sho basaltic volcanics emitted by mildly explosive strombolian activity most of the products are lavas with minor amounts of pyroclastic rocks emplaced mainly during the early stages of activity the transition from the sho to the ks cycle was associated with the collapse of the upper part of the volcanic apparatus the transition from ks to the present day sho activity has been found to have occurred at the time of the sliding of the western portion of the volcano that generated the sciara del fuoco depression the rock series cropping out at stromboli show variable enrichment in potassium incompatible trace elements and radiogenic sr which increase from ca through hkca and sho up to ks rocks major trace element and sr isotopic data agree in indicating that the hkca and sho series evolved by crystal liquid fractionation starting from different parental liquids whereas crustal assimilation appears to have been the leading process during the evolution of ks volcanics mixing processes also played a role although they can be well documented only when they occurred between magmas with different isotopic and geochemical characteristics geochemical modelling based on trace element and isotopic data indicates that the mafic magmas of the different volcanic series may be generated by melting of an upper mantle heterogeneously enriched in incompatible elements and radiogenic sr by addition via subduction of different amounts of crustal material geochemical data however are also in agreement with the alternative hypothesis that the most mafic magmas of the different series have been generated by combined processes of fractional crystallization assimilation and mixing of a ca magma in a deep sited magma chamber the mafic magmas formed by these complex processes were successively emplaced in a shallow reservoir where they evolved by simple fractional crystallization hkca and sho series and by assimilation of crustal material ks the occurrence of changes in the geochemical signatures of the magmas at the time of the structural modification of the volcano is believed to favour the hypothesis that the variable composition observed in the volcanic rocks of stromboli is the result of processes occurring within the volcanic system

persistent polybaric rests of calc alkaline magmas at stromboli volcano italy pressure data from fluid inclusions in restitic quartzite nodules a fluid inclusion study has been performed on quartzite nodules of stromboli volcano hosted by calc alkaline lavas of both the strombolicchio 200 ka and paleostromboli ii 60 ka periods the nodules are mainly composed of quartz crystals with subordinate plagioclase and k feldspar small interstitial minerals such as plagioclase k feldspar clinopyroxene biotite and quartz are also found together with glass muscovite epidote and zircon occur as accessory minerals different quartzite nodules occur 1 equigranular polygonal granoblastic quartzite nodules forming a polygonal texture with clear triple points 2 inequigranular polygonal granoblastic quartzite nodules and 3 break up nodules with strongly resorbed quartz these quartzites are restites from partial melting involving felsic crustal rocks at the magma wall rock contact restitic quartz re crystallises at variable and generally high temperatures leading to the formation of quartzites with different textures quartz grains contain five types of fluid inclusions distinguished on the basis of both fluid type and textural phase relationships at room temperature type i are two phase liquid vapour co2 rich fluid inclusions they are primary and subordinately pseudosecondary in origin and have undergone re equilibration processes type ii mono phase two phase vapour liquid vapour co2 rich fluid inclusions are the most common and based on their spatial distribution and shape they can be divided into two subclasses type iia and type iib type ii inclusions are secondary or pseudosecondary and they are assumed to have formed after decrepitation of type i inclusions and cracking of the host quartz type iii inclusions are mono phase vapour they possibly contain co2 at very low density and surround the inner rims of quartz grains type iv two phase silicate melt inclusions contain glass co2 rich fluid some of them are cogenetic with type ii inclusions finally type v two phase liquid vapour aqueous inclusions are both vapour rich and liquid rich aqueous inclusions microthermometric experiments were performed on both type i and ii inclusions type i inclusions homogenise to liquid between 20 and 30 5 c type iia inclusions homogenise to vapour in the 24 to 30 c range with a maximum peak of frequency at 29 c type iib inclusions also homogenise to vapour between 14 and 25 c there appears to be no difference in homogenisation temperature distribution between the strombolicchio and paleostromboli ii samples the trapping pressures of the fluid inclusions have been obtained by combining the microthermometric data of the strombolicchio and paleostromboli ii samples with the pressure temperature volume i e density characteristics for a pure co2 system the data on the early inclusions type i suggest an important magma rest at a pressure of about 290 mpa i e about 11 km depth type iia co2 inclusions suggest that a second magma rest occurred at a pressure of about 100 mpa i e about 3 5 km depth whereas type iib inclusions were trapped later at a shallower depth during the final magma upwelling no pressure depth differences seem to occur between the strombolicchio and paleostromboli ii periods indicating the same polybaric rests for the calc alkaline magmas of stromboli despite their significantly different ages this persistence in magma stagnation conditions from 200 to 60 ka suggests a similar plumbing system for the present day strombolian activity

a review of age determinations on pleistocene corals in eastern australia abstract samples of corals from all three previously reported pleistocene localities in eastern australia have been dated anew using the 230 th 234 u technique results for two sites are confirmed but the new results for the third site are older than previously reported and do not support a high sea level for isotope substage 5c all sites are now referred to substage 5e

development and emplacement of the inyo domes magmatic suite california evidence from geological textural csd and geochemical observations of ash and lava the inyo domes magmatic system erupted 650 years ago in eastern california it is a series of three lava domes and associated pyroclastic rocks made up of phenocryst poor fp and phenocryst rich compositions cp we examined the chemical composition quantitative petrographic texture and geology of the ensemble the fp unit has considerable compositional variation that was produced by fractional crystallisation of feldspars and pyroxenes in a plexus of conduits and magma storage areas under or close to the inyo domes magmatic system there is no magmatic link with the synchronous north mono silicic eruption 20 km to the north the cp unit is compositionally more uniform and originated from a mushy feldspar cumulate formed in an earlier rhyolitic magma chamber the eruption started with the reactivation of a major fault which ruptured the surface initially the fault intersected a single hydrous magma source in the plexus and produced a pyroclastic eruption in the south other regions of the plexus to the north were rapidly co opted making further pyroclastic eruptions as the magmas became degassed lava domes started to form from fissures finally the cp magma source became reactivated by the injection of new magma felsic or mafic into the chamber the cp magma was forced out into a conduit of the fp unit where it formed a mixed unit im the quantity of the cp component increased until it dominated at this point the fp units were solid and the cp unit piled up to make the central knobs of the southern domes

passive acoustic monitoring using a towed hydrophone array results in identification of a previously unknown beaked whale habitat beaked whales are diverse and species rich taxa they spend the vast majority of their time submerged regularly diving to depths of hundreds to thousands of meters typically occur in small groups and behave inconspicuously at the surface these factors make them extremely difficult to detect using standard visual survey methods however recent advancements in acoustic detection capabilities have made passive acoustic monitoring pam a viable alternative beaked whales can be discriminated from other odontocetes by the unique characteristics of their echolocation clicks in 2009 and 2010 pam methods using towed hydrophone arrays were tested these methods proved highly effective for real time detection of beaked whales in the southern california bight scb and were subsequently implemented in 2011 to successfully detect and track beaked whales during the ongoing southern california behavioral response study the three year field effort has resulted in 1 the successful classification and tracking of cuvier s ziphius cavirostris baird s berardius bairdii and unidentified mesoplodon beaked whale species and 2 the identification of areas of previously unknown beaked whale habitat use identification of habitat use areas will contribute to a better understanding of the complex relationship between beaked whale distribution occurrence and preferred habitat characteristics on a relatively small spatial scale these findings will also provide information that can be used to promote more effective management and conservation of beaked whales in the scb a heavily used naval operation and training region

climate driven changes in tropical cyclone intensity shape dune activity on earth s largest sand island abstract in this study historical aerial photos and detailed climatic time series are used to show the geomorphological consequences of a significant decrease in tropical cyclone frequency and intensity in eastern australia since the early 1980s leading to rapid dune stabilization on earth s largest sand island and a world heritage site fraser island australia it is shown that cyclone frequency and intensity significantly declined in eastern australia south of 20 s since the early 1980s corresponding with the shift to a positive phase of the interdecadal pacific oscillation in 1977 and an increased frequency of enso events since 1982 83 using historical aerial photos and remote sensing techniques it is shown that most of fraser island s transgressive dune fields were advancing inland during the period between 1948 and 1982 and that tropical cyclones in that period were strong enough to initiate small blow outs

late holocene cliff top blowout activation and evolution in the cooloola sand mass south east queensland australia cliff top dunes are a locally important geomorphic features of sedimentary coasts they are traditionally interpreted as being sourced by or with sand derived from the beach below the cliff this paper presents the results of a stratigraphic and geochronological study of carlo sand blow a coastal blowout that has developed on top of a high sandy cliff in the cooloola sand mass south east queensland we use a combination of sedimentological pedological and geophysical techniques along with optically stimulated luminescence dating to determine the depositional history and evolution of the blowout we demonstrate that the blowout is dominantly nourished by sand eroded from its floor rather than the adjacent beach the original dune surface dates to the first half of the last glacial period c 40 70 ka and this dune was deflated in the late holocene dune activity is directly associated with cliff undercutting because of coastal retreat in the late holocene but coastal erosion on its own is not capable of maintaining aeolian activity blowout activity occurred between 2 6 and 2 3 ka and again at 0 3 ka with aeolian sand burying palaeosols both soil surfaces contained charcoal and tree stumps in growth position and our study suggests that fire is the immediate trigger for blowout reactivation it is likely that these fires were anthropogenic in origin because the site is somewhat protected from natural fire and the ages coincide with intensification of human use of coastal sites in the area

the 2007 eruption of stromboli volcano insights from real time measurement of the volcanic gas plume co2 so2 ratio abstract the recent eruption of stromboli in february april 2007 offered a unique chance to test our current understanding of processes driving the transition from ordinary persistent strombolian to effusive activity and the ability of instrumental geophysical and geochemical networks to interpret and predict these events here we report on the results of two years of in situ sensing of the co 2 so 2 ratio in stromboli s volcanic gas plume in the attempt to put constraints on the trigger mechanisms and dynamics of the eruption we show that large variations of the plume co 2 so 2 ratio range 0 9 26 preceded the onset of the eruption since december 2007 interrupting a period of relatively steady and low ratios time averaged ratio 4 3 lasting from at least may to november 2006 by contrasting our observations with numerical simulations of volcanic degassing at stromboli derived by use of an equilibrium saturation model we suggest that the pre eruptive increase of the ratio reflected an enhanced supply of deeply derived co 2 rich gas bubbles to the shallow plumbing system this larger than normal ascent of gas bubbles was likely sourced by a 1 3 km deep gas melt separation region probably a magma storage zone and caused faster convective overturning of magmas in the shallow conduit an increase in the explosive rate and in seismic tremor and finally the collapse of the la sciara del fuoco sector triggering the effusive phase the high co 2 so 2 ratios up to 21 observed during the effusive phase and particularly in the days and hours before a paroxysmal explosion on march 15 2007 indicate the persistence of the same gas source and suggest that de pressurization of the same 1 3 km deep magma storage zone could have been the trigger mechanism for the paroxysm itself

varved lacustrine sediments of lake tougou ike western japan with reference to holocene sea level changes in japan abstract eighteen metres of laminated sediments were recovered in a holocene sediment core taken from lake tougou ike in 1992 the lamination evident from the alternation of light and dark coloured laminae records cyclic deposition of biochemical sediments annual environmental changes in and around the lake caused seasonal variations in sediment flux to the lake floor explaining these cyclic variations in sedimentary facies ams 14 c dating of organic remains from 40 horizons in the succession supports the interpretation of each light to dark couplet as an annual increment each laminated couplet is identified as a non glacial varve formed mainly by seasonal changes in diatom productivity varve counting and 14 c dating provide a detailed holocene chronological framework with time resolution on the order of individual years within which to reconstruct paleoenvironmental changes recorded in the sediment core holocene relative sea level changes at lake tougou ike were estimated with 10 yr precision using the variable authigenic iron mineral content of the sediment as a proxy the results demonstrate that the relative sea level at lake tougou ike rose abruptly at about 8900 7700 5600 4000 3600 and 2700 cal yr bp and decreased gradually in the intervening intervals these relative rises in sea level are demonstrated to be coeval with ice sheet discharge events recorded in sediment cores from the north atlantic ocean abrupt coastal environmental changes caused by sea level changes likely took place throughout the japanese islands and will probably be identified in both the holocene and the last glacial interval the latter being a time when dansgaard oeschger cycles were clearly active in the north atlantic region

beaked whale and dolphin tracking using a multichannel autonomous acoustic recorder to track highly directional echolocation clicks from odontocetes passive hydrophone arrays with small apertures can be used to receive the same high frequency click on each sensor a four hydrophone small aperture array was coupled to an autonomous acoustic recorder and used for long term tracking of high frequency odontocete sounds the instrument was deployed in the spring of 2009 offshore of southern california in a known beaked whale and dolphin habitat at about 1000 m depth the array was configured as a tetrahedron with approximately 0 5 m sensor spacing time difference of arrival measurements between the six sensor pairs were used to estimate three dimensional bearings to sources both near seafloor beaked whales and near sea surface dolphins were tracked the tracks observed using this technique provide swimming and diving behavioral information for free ranging animals using a single instrument furthermore animal detection ranges were derived allowing for estimation of detection probability functions

smooth or oscillating late holocene sea level curve evidence from cross regional statistical regressions of fixed biological indicators abstract what if any is the pattern of change of the late holocene sea level curve if a common pattern exists can it be better discerned in the non glaciated tectonically stable regions of the southern hemisphere and is sea level data more reliable from one type of marine sample than another to begin an investigation of these questions we present a review of regressing time elevation plots from the low to mid latitudes of the southern hemisphere based upon the differential between modern and past levels of various fixed biological indicators mainly calcareous tubeworms and corals stranded up to 2 m above present relative sea levels the sample sets come from our work in southeast australia and comparable work from north east australia the pacific islands and brazil we show that using evidence obtained from fixed intertidal tubeworm species there is no statistical exclusivity between the smooth and oscillating polynomials but corals are more problematic in situ tubeworm species with their reduced error bars in comparison to corals fulfil the condition of providing more robust results for statistical analysis regression curves based on these species point to cross regional similarities in the pattern of sea level movement of the last 6000 years across the lower latitudes of the southern hemisphere these statistical exercises while not able to yield definitive conclusions can highlight statistically equally likely alternative patterns of sea level movement which can then be tested by field evidence they can also give useful indications of the quality of sea level data obtained from different biological sources as in the difficulties in the use of corals compared to common intertidal tubeworm species

spatial patterns in the mineralogy of island arc magma series sangihe arc indonesia the 500 km long sangihe arc is the western of two colliding arcs in northeastern indonesia in its basalts olivine magnetite crystallization is followed either by plagioclase the plagioclase basalt series pbs or augite the augite basalt series abs pbs occur at or near the southern volcanic front and evolve to two pyroxene andesites abs occur behind the volcanic front and to the north where collision is more complete evolve to hornblende andesites and have higher aliv in calcic clinopyroxene both tholeiitic th and calcalkaline ca fe enrichment trends occur in pbs whereas abs are only ca th suites occur only at the southern volcanic front have low lile concentrations k55 1 and low cao al2o3 0 6 ca suites occur more widely have variable lile k55 0 6 2 0 more modal magnetite in andesites higher modal clinopyroxene plagioclase ratios and cao al2o3 0 6 0 9 in basalts quench temperatures are 1110 880 c in basalt to rhyolite temperatures are higher in andesites from the volcanic front than behind it oxygen fugacity is from qfm to above nno silica activity decreases and lile concentrations increase away from the volcanic front consequently ph2o is lowest whereas andesite temperatures plus the percentage of mantle fusion are highest at the southern volcanic front where there is the least coupling between plates

reconnaissance thermoluminescence dating of northern australian coastal dune systems abstract quaternary lithostratigraphic units in coastal dunes have been dated at three locations in northern australia cobourg peninsula shelburne bay and cape flattery by both radiocarbon dating of shell and organic carbon and thermoluminescence tl sediment dating both coarse fraction and fine fraction tl methods were used seventeen tl dates were measured none of the tl dates contradict the ages given by radiocarbon where multiple tl dates were taken from a unit they overlap within 2 standard deviation giving added confidence in the results a phase of dune emplacement during the late holocene ca 2700 1800 yr b p was identified in two of the dune fields an early holocene phase of dune emplacement ca 8600 7500 yr b p in two of the dune fields and a late pleistocene episode ca 24 000 17 000 yr b p in both the cape york dunefields three older units gave dates of about 29 000 81 000 and 171 000 yr b p but these must be treated with caution

on the deformation and freezing of enclaves during magma mixing abstract mixing of an enclave of hot mafic magma into cooler silicic magma involves the competing effects of heat transfer acting to rigidify the enclave and viscous shearing imposed by a flowing host magma acting to deform and disperse the enclave we model the time required to grow a rigid chilled margin and compare this with the time required to deform the initially hot enclave whether an enclave will deform before it freezes depends on the ratio of the thermal and deformation timescales pe app 3 a 2 s r 2 and the dimensionless rigidification temperature t r t s t m t s where app is the applied shear stress a is the enclave radius is the thermal diffusivity s is the viscosity of the host r is the strength of the chilled rind t r is the temperature at which the enclave attains strength r and t m and t s are the initial temperatures of the mafic enclave and silicic host according to the model small values of pe and large values of promote rapid rigidification the model is verified by laboratory experiments on the flow and freezing of polyglycol wax droplets in cold water geological observations show that correlations between enclave size degree of deformation and local shear stress match the model s predictions studies of enclave size and shape as functions of eruption rate and position within lava flows and minor intrusions offer a new technique for studying magma flow processes during eruptions

mid late holocene sea level variability in eastern australia a re analysis of sea level data from eastern australia based on 115 calibrated c 14 ages is used to constrain the origin timing and magnitude of sea level change over the last 7000 years we demonstrate that the holocene sea level highstand of 1 0 1 5 m was reached 7000 cal yr bp and fell to its present position after 2000 yr bp these findings are in contrast to most previous studies that relied on smaller datasets and did not include the now common conversion of conventional c 14 ages to calendar years during this 5000 year period of high sea level growth hiatuses in oyster beds and tubeworms and lower elevations of coral microatolls are interpreted to represent short lived oscillations in sea level of up to 1 m during two intervals beginning c 4800 and 3000 cal yr bp the rates of sea level rise and fall 1 2 mm yr 1 during these centennial scale oscillations are comparable with current rates of sea level rise the origin of the oscillations is enigmatic but most likely the result of oceanographic and climatic changes including wind strengths ice ablation and melt water contributions of both greenland and antarctic ice sheets

microatolls as sea level indicators on a mid ocean atoll microatolls are discoid corals with flat upper surfaces that develop when upward coral growth is constrained by exposure at low tide they have been widely viewed as important and relatively precise indicators of modern and paleo sea level positions because of their sensitivity to the water air interface though this has rarely been directly established by survey to a precise datum this study involved an accurate survey of 282 microatolls growing in a range of intertidal environments open reef flats interisland passages lagoons across the cocos keeling islands a mid ocean atoll in the indian ocean the upper surface elevation of modern microatolls was found to vary through more than 40 cm across the environments in which these corals occur on cocos representing more than 30 of the spring tide range much of the variation reflects subtle ponding at low water levels across extensive low gradient reef surfaces associated with interisland passages microatolls in open reef flat habitats are typically constrained within the narrowest and most consistent elevation range around the atoll the environment in which individual fossil microatolls occurred when they were alive is significant in reconstructing former sea levels

last glacial maximum and last glacial interglacial transition pollen record from northern nsw australia evidence for a humid late last glacial maximum and dry deglaciation in parts of eastern australia this paper presents the results of a palynological investigation into the late last glacial maximum lgm and last deglaciation ca 20 000 9000 cal a bp from little llangothlin lagoon in the sub tropics of eastern australia the lagoon held permanent water during the late lgm and early deglaciation but was intermittently dry during the late deglaciation during the late lgm local vegetation was dominated by a sub alpine herbfield but the significant presence of rainforest taxa in the pollen record indicates the survival of rainforest rainforest margin or wet sclerophyll communities close to the site by ca 17 000 cal a bp open eucalyptus forest replaced the alpine herbfield vegetation indicating that warming had commenced rainforest taxa disappeared at this time but re appeared at the end of the deglaciation the lgm conditions are consistent with a dominant circulation system whereby persistent high pressure over eastern australia brings onshore easterlies to this region and maintains humid conditions along the east coast and highlands of the great dividing range this is similar to modern winter circulation but the persistence of rainforest and wet sclerophyll taxa suggests an increase in easterly flow over modern conditions during the lgm

recent eruptive history of stromboli aeolian islands italy determined from high accuracy archeomagnetic dating 1 the large sample method of archeomagnetic dating was applied to stromboli 127 samples 10 sites yielded paleofield directions with 95 confidence intervals less than 2 coupled with a reference curve for secular variation in western europe these allow accurate dating of volcanic events a lava flow underlying san bartolo village gave a minimum age of ad 100 100 a lava overflow predating the last sector collapse was dated from 1350 60 suggesting the recent occurrence of highly hazardous events lava spatters and a hot avalanche high on the northern flank were emplaced during the xxth century lava spatters on the lower flanks could date the onset of the still ongoing phase from ad 550 50 these results are different from those obtained in a recent study probably because traditional paleomagnetic sampling cannot yield sufficient precision considering the characteristics of the archeomagnetic secular variation curve