slip distribution from the 1 april 2007 solomon islands earthquake a unique image of near trench rupture 1 we estimate the slip distribution from the mw 8 1 solomon islands earthquake in 2007 from two post seismic surveys measuring uplifted coral and submerged coastal features the occurrence of islands extremely proximal to the trench and nucleation of rupture allowed for the collection of unprecedented coseismic deformation dataset along a large megathrust earthquake using data from the two surveys along the southeastern half of the slip zone within five weeks of the event we model the elastic dislocation to identify the optimal 29 and alternate 20 dip and distribution of thrust along the southern rupture the vertical deformation which includes both coseismic and early postseismic deformation has highly variable and large slip within 25 km of the trench and straddling ranongga island the shallow focus of slip in the near trench area may explain the locally high tsunami run up on portions of simbo island however the aseismic contribution of afterslip remains unknown

mesozoic cenozoic tectonic relationships between the kuqa subbasin and tian shan northwest china constraints from depositional records abstract stratigraphic profiles in the kuqa subbasin located along the southern flank of the tian shan northwest china display similar mesozoic cenozoic evolutionary sequences of compositional maturity exist in conglomerate clasts sandstone framework grains and detrital heavy minerals the similarity of these time series profiles resulted from orogenesis and intracontinental deformation of the provenance area the ancestral tian shan mineralogical maturities of conglomerates and sandstones increase from triassic to middle jurassic and decrease from upper jurassic lower cretaceous to tertiary this trend parallels a similar decrease in maturity in detrital heavy minerals zircon rutile and tourmaline dominate in middle upper triassic to middle jurassic sandstone whereas unstable hornblende and pyroxene dominate the heavy mineral suites in the tertiary especially in miocene and pliocene strata these compositional trends are coeval with gradual southward migration of alluvial depositional fronts and depositional depocenters from cretaceous to miocene since the pliocene large scale southward migration of alluvial depositional systems occurred while depositional depocenters migrated northward based on the mesozoic cenozoic depositional records the tectonic evolution of the tian shan kuqa subbasin may be divided into five phases 1 in early triassic following compression and uplift since permian gravelly braided river alluvial plain depositional systems developing in the kuqa subbasin characterized by sands of mixed orogenic provenance type derived from the ancestral tian shan 2 from middle triassic to middle jurassic sediment composition of the kuqa subbasin reflects arc orogen and mixed orogenic sand types with extensive planation of the ancestral tian shan and the development of relatively stable coal bearing depositional environments 3 renewed compression uplift of the tian shan occurred in late mesozoic especially in cretaceous with most detrital modes of the kuqa subbasin indicating provenance attributes akin to the south tian shan 4 further intensive compression uplift and probably southward basinward propagation of the south tian shan occurred during miocene and 5 supracrustal gravity gliding and collapse occurred in the tian shan kuqa subbasin probably due to intensive deep compression with rejuvenated uplift and probable southward basinward structural propagation of the south tian shan developing since pliocene observed changes in sediment composition and depositional environment since pliocene time were also controlled by frequent and abrupt climate changes in addition to intensive uplift of the tian shan moreover all depositional records in the kuqa subbasin seem to reflect west to east differences in provenance along the tian shan probably indicating greater exhumation depth in the western tian shan than that in the eastern tian shan since early cretaceous

measuring the sea ice floe size distribution sea ice is broken into floes whose diameters range from meters to a hundred kilometers this fragmentation affects the resistance of the ice cover to deformation and the melting at floe sidewalls in summer floes are broken by waves and swell near the ice edge and throughout the pack by isostatic imbalances thermal cracking winds and currents in winter they are welded together by freezing floe size can be measured by several properties p for instance area or mean caliper diameter two definitions of floe size distribution seem useful f p the fraction of area covered by floes no smaller than p and n p the number of floes per unit area no smaller than p f p can be measured by sets other than areas such as the fraction of a line or of a point set covered by floes no smaller than p if n behaves like for small where is mean caliper diameter must be greater than 2 so that the small floes occupy finite area if 2 1 the perimeter of small floes is infinite several summertime distributions have been measured on a log log graph their slopes local values of range from 1 7 to 2 5 one distribution follows a power law the others have steeper slopes for larger floes and more gradual slopes for smaller floes another sampling strategy is to measure the lengths of line segments on floes the distribution of these chord lengths is equivalent to the distribution of floe diameters the variance of an estimate of the fraction g of area covered by floes in any size range is g 1 g k 1 where k is the equivalent number of independent samples k can be found from the autocovariance of the indicator function for the chosen size range for line sampling of a narrow range of floe diameters k is the ratio of the sample length to the floe diameter

petrography and provenance of the early permian fluvial warchha sandstone salt range pakistan abstract the warchha sandstone of the salt range of pakistan is a continental succession that accumulated as part of a meandering fluvial system during early permian times several fining upward depositional cycles are developed each of which is composed of conglomerate cross bedded sandstone and in their upper parts bioturbated siltstone and claystone units with distinctive desiccation cracks and carbonate concretions clast lithologies are mainly of plutonic and low grade metamorphic origin with an additional minor sedimentary component textural properties of the sandstone are fine to coarse grained poorly to moderately sorted sub angular to sub rounded and with generally loose packing based on modal analyses the sandstone is dominantly a feldspathoquartzose arkose to sub arkose detrital constituents are mainly composed of monocrystalline quartz feldspars more k feldspar than plagioclase and various types of lithic clasts xrd and sem studies indicate that kaolinite is the dominant clay mineral and that it occurs as both allogenic and authigenic forms however illite illite smectite mixed layer smectite and chlorite are also recognised in both pores and fractures much of the kaolinite was likely derived by the severe chemical weathering of previously deposited basement rocks under the influence of a hot and humid climate transported residual clays deposited as part of the matrix of the warchha sandstone show coherent links with the sandstone petrofacies thereby indicating the same likely origin illite smectite and chlorite mainly occur as detrital minerals and as alteration products of weathered acidic igneous and metamorphic rocks based primarily on fabric relationship the sequence of cement formation in the warchha sandstone is clay generally kaolinite iron oxide calcareous and siliceous material before iron rich illite and occasional mixed layer smectite illite and rare chlorite both petrographic analysis and field characteristics of the sandstone indicate that the source areas were characterised by uplift of a moderate to high relief continental block that was weathered under the influence of hot and humid climatic conditions the rocks weathered from the source areas included primary granites and gneisses together with metamorphic basement rocks and minor amounts of sedimentary rocks regional palaeogeographic reconstructions indicate that much of the warchha sandstone detritus was derived from the aravalli and malani ranges and surrounding areas of the indian craton to the south and southeast before being transported to and deposited within the salt range region under the influence of a semi arid to arid climatic regime

ice floe distribution in the sea of okhotsk in the period when sea ice extent is advancing 1 ice floe distribution in the sea of okhotsk during a cold air outbreak was investigated by analyzing several thousand of sea ice images obtained by the aircraft observation on 18 february in 2000 the effective floe size became small from 10 m to 2 m within the marginal ice zone miz the scaling properties of floe distribution are demonstrated by a cumulative number frequency which follows a power law scaling with an exponent the value of increased from 1 5 within the internal ice zone to 2 1 within the miz which means that relatively small ice floes dominate in the miz the effective width of the miz estimated by a wave attenuation theory agreed with the observed width suggesting that the flexural stress of waves penetrating into the ice is one of the possible mechanisms which cause the difference in the scaling property

depositional systems composition and geochemistry of triassic rifted continental margin redbeds of the internal rif chain morocco the middle to upper triassic redbeds at the base of the ghomaride and internal dorsale calcaire nappes in the rifian sector of the maghrebian chain have been studied for their sedimentological petrographic mineralogical and chemical features redbeds lie unconformably on a variscan low grade metamorphic basement in a 300 m thick upward fining and thinning megasequence successions are composed of predominantly fluvial red sandstones with many intercalations of quartzose conglomerates in the lower part that pass upwards into fine grained micaceous siltstones and massive mudstones with some carbonate and evaporite beds this suite of sediments suggests that palaeoenvironments evolved from mostly arenaceous alluvial systems middle triassic to muddy flood and coastal plain deposits the successions are characterized by local carbonate and evaporite episodes in the late triassic the growth of carbonate platforms is related to the increasing subsidence norian rhaetian during the break up of pangea and the earliest stages of the western tethys opening carbonate platforms became widespread in the sinemurian sandstones are quartzose to quartzolithic in composition testifying a recycled orogenic provenance from low grade palaeozoic metasedimentary rocks palaeoweathering indices chemical index of alteration chemical index of weathering and plagioclase index of alteration suggest both a k enrichment during the burial history and a source area that experienced intense weathering and recycling processes these processes were favoured by seasonal climatic alternations characterized by hot episodically humid conditions with a prolonged dry season these climatic alternations produced illitization of silicate minerals iron oxidation and quartz rich red sediments in alluvial systems the estimated burial temperature for the continental redbeds is in the range of 100 to 160 c with lithostatic tectonic loading of ca 4 to 6 km these redbeds can be considered as regional petrofacies that mark the onset of the continental rift valley stage in the western pangea middle triassic before the opening of the western part of tethys in the middle jurassic the studied redbeds and the coeval redbeds of many alpine successions betic tellian and apenninic orogens show a quite similar history they identify a mesomediterranean continental block originating from the break up of pangea which then played an important role in the post triassic evolution of the western mediterranean region

landslide generated tsunami and particle transport in mountain lakes and reservoirs gravitational mass flows may generate tsunamis as they hit water bodies such as oceans reservoirs or mountain lakes upon impact they can generate tremendous particle laden or debris flows and floods rapidly cascading waves down mountain slopes can trigger debris flows or floods potentially causing huge damage to civil structures and endangering life here we apply a general two phase mass flow model pudasaini 2012 and present three dimensional 3 d high resolution simulations for a real two phase debris impacting a fluid reservoir an innovative formulation provides an opportunity within a single framework to simulate simultaneously the sliding two phase debris landslide reservoir debris impact at reservoir water wave generation propagation and mixing and separation between solid and fluid phases the results demonstrate formation and propagation of very special solid and fluid structures in the reservoir propagation of submarine debris turbidity currents and complex interactions between the subaerial debris surface tsunami and submarine debris waves our results reveal that the submerge timescaling for a deformable two phase debris deviates substantially from the same for a non deformable solid these results substantially increase our understanding of 3 d complex multiphase systems flows this allows for the proper modeling of landslide debris induced mountain tsunami dynamics of turbidity currents and highly concentrated sediment transports in himalayan and alpine slopes and channels with associated applications to engineering environmental and hazard mitigation plans

tsunamis from the 29 march and 5 may 2015 papua new guinea earthquake doublet m w 7 5 and tsunamigenic potential of the new britain trench we characterized tsunamis from the 29 march and 5 may 2015 kokopo papua new guinea mw 7 5 earthquake doublet teleseismic body wave inversions using various rupture velocities vr showed similar source time functions and waveform agreements but the spatial distributions of the slips were different the rupture durations were 45 and 55 s for the march and may events with their peaks at 25 and at 17 s respectively tsunami simulations favored source models with vr 1 75 and 1 50 km s for the march and may earthquakes the largest slip on the fault was similar 2 1 and 1 7 m but the different depths and locations yielded maximum seafloor uplift of 0 4 and 0 2 m tsunami simulation from hypothetical great earthquakes m 8 4 and 8 5 on the new britain trench showed that tsunami amplitudes may reach up to 10 m in rabaul but most tsunami energy was confined within the solomon sea

twin tsunamis triggered by the 12 january 2010 haiti earthquake on 12 january 2010 a magnitude m w 7 0 earthquake occurred 25 km west southwest of haiti s capital port au prince causing an estimated 316 000 fatalities thereby exceeding any previous loss of life from a similar size earthquake in addition tsunami waves triggered by the earthquake caused at least three fatalities at petit paradis due to a complete lack of tsunami awareness the international tsunami survey team itst was deployed within weeks of the event and covered the greater bay of port au prince and more than 100 km of hispaniola s southern coastline the collected survey data include more than 21 tsunami heights along with observations of coastal land level change maximum tsunami heights of 3 m have been measured for two independently triggered tsunamis

sandstone provenance of north western sectors of the intracontinental cenozoic qaidam basin western china tectonic vs climatic control abstract sandstone samples from all cenozoic formations of the nonmarine internally drained qaidam basin have been collected for provenance analysis to monitor possible changes in sandstone composition driven either by tectonics or climate provided an appropriate hinterland biotite contents may be a reasonable indicator for aridity moderately sorted sandstones with subangular to subrounded grains from the northwestern part of the qaidam basin are immature indicated by a high proportion of feldspars and lithic fragments nevertheless they have relatively high quartz contents of 29 65 averaging between 40 and 45 the average framework compositions of the formations show only a slight variation over time limited to the oldest and youngest cenozoic formations contents of white mica and biotite are significantly higher in upper portions of the section white mica contents increases from 1 0 to 3 7 and biotite from 0 1 to 1 6 respectively this change can be explained by increasing aridity during neogene and surface uplift of altyn mountains and qimantagh which led to higher relief when plotted on basic variation diagrams total quartz feldspar lithic fragments there is a slight shift from continental block field to orogenic field which might reflect the motion of the altyn tagh fault since oligocene times although climate changed during the cenozoic from arid over semiarid back to arid we could not find any distinct changes in the framework mineral compositions over time that could be related to climatic events few selected mudstones from eocene to lower miocene formations have been geochemically analysed by icp ms all samples display uniform high enrichment in light rees in chondrite normalized diagrams with one exception the ree concentrations are decreasing in a stepwise manner although insignificantly from formation to formation with time due to a diluting effect by carbonate

observed changes in sea ice floe size distribution during early summer in the western weddell sea abstract digital aerial photographs are used to measure the change in floe size distribution over an area of the western weddell sea during the ice station polarstern ispol program the results show a significant increase in the number of small floes and brash ice over a 23 day period from 9 december 2004 to 1 january 2005 this is attributed to a net divergence of the pack ice coupled with ice melt that caused ridges to relax and break into their component parts the net effect is a significant increase in total floe perimeter that is important for lateral melt and primary production near floe edges

the effect of a storm on the 1992 summer sea ice cover of the beaufort chukchi and east siberian seas for the summer beaufort chukchi and east siberian seas a variety of active and passive microwave satellite data are used to determine the response of the ice edge and interior to a storm specifically the study concentrates on a low pressure system that passed over the region between august 14 and 20 1992 with peak geostrophic winds of about 18 m s 1 through the use of the ers 1 imaging radar and the special sensor microwave imager the ice response is examined at two locations at the ice edge for a nearly stationary location in the chukchi sea and in the ice interior along three swaths in the beaufort chukchi and east siberian seas the ice edge observations show that the storm fractures the large floes into small floes some of which are advected into the adjacent warm water the ice interior observations show that the storm caused an increase in the open water amount and a shift in the floe size distribution toward smaller floes in the ice interior application of the cumulative number distribution n d where n is the number of floes per unit area that are no smaller than some floe diameter d shows that for d 1 km n behaves like d where lies in the range 1 8 2 9 our analysis also shows that this slope is not affected by the storm and is slightly larger near the ice edge

power scaling and seasonal changes of floe areas in the arctic east siberian sea the cumulative number versus floe area distribution of seasonal sea floes from six satellite images of the arctic ocean during the summer breakup and melting is fit by two scale invariant power law scaling regimes for floe areas ranging from 30 to 28 400 000 m2 scaling exponents for larger floe areas range from 0 6 to 1 0 with an average of 0 8 scaling exponents for smaller floe areas range from 0 3 to 0 6 with an average of 0 5 the inflection point between the two scaling regimes ranges from 283 102 to 4850 102 m2 and generally moves from larger to smaller floe areas through the summer melting season the stability of the power scaling results is demonstrated for two of the images by dividing each in half and analyzing each half separately with the result that the scaling exponents and the size of the inflection points are nearly the same for each half as for the whole image we propose that the two scaling regimes and the inflection between them are established during the initial breakup of sea ice solely by the process of fracture the distributions of floe size regimes retain their scaling exponents as the floe pack evolves from larger to smaller floe areas from the initial breakup through the summer season due to grinding crushing fracture and melting the scaling exponents for floe area distribution are in the same range as those reported in previous studies of arctic floes and for the single scaling exponents found for crushed and ground geologic materials including streambed gravel lunar debris and artificially crushed quartz the single scaling exponent found for fault gouge falls below the range for floes possibly because the fracturing and grinding process in fault gouge takes place under high confining pressure a probabilistic model of fragmentation is proposed that generates a single power law scaling distribution of fragment size

characteristics of sea ice floe size distribution in the seasonal ice zone 1 the size distribution of sea ice floes was observed by coordinated landsat imagery and video monitoring conducted from an icebreaker and a helicopter for an area 38 km 26 km in seasonal sea ice in the southern sea of okhotsk in february 2003 the combination of imagery on several scales allowed measurements of ice floes over three orders of magnitude from 1 m to 1 5 km two different regimes were observed floes larger than about 40 m have a power law number density with an exponent of 1 87 in the lower range of earlier results below 40 m the power law exponent is 1 15 the cause of these two different regimes is hypothesized to lie in the effects of swell on floes of different sizes and thicknesses the importance of the floe size distribution for lateral melting is elucidated

coral reefs as buffers during the 2009 south pacific tsunami upolu island samoa abstract the coral reef bordering the coastline of samoa affected by the 29 september 2009 tsunami provides a variety of ecosystem services from nurseries for fisheries and inshore source of food for local communities to aesthetics for tourists and the width of the lagoon may have been a factor in reducing the onshore wave height to understand the complex interactions between the onshore human population and the offshore coral we formed an interdisciplinary survey team to document the effects the tsunami had on the nearshore coral reef and how these changes might affect local inhabitants the scale of reef damage varied from severe where piles of freshly killed coral fragments and mortality were present to areas that exhibited little impact despite being overrun by the tsunami we found that many coral colonies were impacted by tsunami entrained coral debris which had been ripped up and deposited on the fore reef by repeated cyclones and storm waves in other places large surface area tabular coral sustained damage as the tsunami velocity increased as it was funneled through channels areas that lacked debris entrained by the waves as well as areas in the lee of islands came through relatively unscathed with the exception of the delicate corals that lived on a sandy substrate in the lagoon on the south coast with its steep topography coral colonies were damaged by tsunami generated debris from onshore entrained in the backwash despite the potential for severe tsunami related damage there were no noticeable decreases in live coral cover between successive surveys at two locations although algal cover was higher with the increased nutrients mobilized by the tsunami while there was an immediate decrease in fish takes in the month following the tsunami when supporting services were likely impacted both volume and income have rapidly increased to pre tsunami levels long term monitoring should be implemented to determine if nursery services were affected

sandstone composition of the upper jurassic emuerhe formation from the mohe basin china the sandstone composition analysis carried out on the samples from three different sections western section middle section and eastern section of the upper jurassic emuerhe formation in the mohe basin northeastern china reveals that the okhotsk orogenic belt and the ergun massif basement are the source areas for the emuerhe formation the source area of the western section and the a segment of the middle section is the okhotsk orogenic belt the tectonic attributes of the okhotsk orogenic belt are those of a dissected arc the transportation distance of clastic rocks from these sections gradually lengthened and the uplift rate of the okhotsk orogenic belt gradually increased the source area of the eastern section and the b segment of the middle section is the ergun massif basement compared with the okhotsk orogenic belt the tectonic attributes and uplift rate of the ergun massif basement are different from the former the attributes of the ergun massif basement are those of basement uplift the transportation distance of clastic rocks from the eastern section and the b segment of the middle section gradually shortened and the uplift rate of the ergun massif basement gradually decreased these conclusions are consistent with the characteristics of a foreland basin thus we can draw the conclusion that the mohe basin belongs to the foreland basin

seismic velocity structure beneath the western solomon islands from the joint inversion of receiver functions and surface wave dispersion curves abstract an mw 8 1 earthquake occurred in 2007 and induced a tsunami that hit the western solomon islands and caused casualties this motivated us to deploy a seismic network around the rupture zone of the 2007 event to investigate the seismic velocity structure of the western solomon islands we select seismograms of teleseismic events recorded by our seismic network joint inversion of p wave receiver functions and surface wave group velocity dispersion curves is used to estimate station based 1 d velocity models the resulting velocity models show a highly variable crustal structure across the region the moho depths beneath the stations range from 25 to 40 km a low velocity zone lvz is observed at most seismic stations in this work our study provides preliminary station based seismic velocity models for the study region and more stations will be deployed in the continuing project an integrated 3 d velocity model will be determined in the future

a great earthquake rupture across a rapidly evolving three plate boundary on 1 april 2007 a great tsunamigenic earthquake moment magnitude 8 1 ruptured the solomon islands subduction zone at the triple junction where the australia and solomon sea woodlark basin plates simultaneously underthrust the pacific plate with different slip directions the associated abrupt change in slip direction during the great earthquake drove convergent anelastic deformation of the upper pacific plate which generated localized uplift in the forearc above the subducting simbo fault potentially amplifying local tsunami amplitude elastic deformation during the seismic cycle appears to be primarily accommodated by the overriding pacific forearc this earthquake demonstrates the seismogenic potential of extremely young subducting oceanic lithosphere the ability of ruptures to traverse substantial geologic boundaries and the consequences of complex coseismic slip for uplift and tsunamigenesis

tsunamigenic earthquakes past and present milestones we review a number of events which taken individually have significantly affected our understanding of the generation of tsunamis by earthquake sources and our efforts at mitigating their hazards notably through the development of warning algorithms starting with the 1700 cascadia earthquake we examine how significant tsunamis have changed our views in fields as diverse as seismotectonics the diversity of earthquake cycles the development of warning algorithms the response of communities at risk to warnings and their education the latter being either formal or rooted in ancestral heritage we discuss in detail lessons from the 2004 sumatra disasters and review the performance of warning centers and the response of affected populations during the nine significant tsunamis which have taken place since 2004

comparative study of two tsunamigenic earthquakes in the solomon islands 2015 mw 7 0 normal fault and 2013 santa cruz mw 8 0 megathrust earthquakes the july 2015 mw 7 0 solomon islands tsunamigenic earthquake occurred 40 km north of the february 2013 mw 8 0 santa cruz earthquake the proximity of the two epicenters provided unique opportunities for a comparative study of their source mechanisms and tsunami generation the 2013 earthquake was an interplate event having a thrust focal mechanism at a depth of 30 km while the 2015 event was a normal fault earthquake occurring at a shallow depth of 10 km in the overriding pacific plate a combined use of tsunami and teleseismic data from the 2015 event revealed the north dipping fault plane and a rupture velocity of 3 6 km s stress transfer analysis revealed that the 2015 earthquake occurred in a region with increased coulomb stress following the 2013 earthquake spectral deconvolution assuming the 2015 tsunami as empirical green s function indicated the source periods of the 2013 santa cruz tsunami as 10 and 22 min

extreme runup from the 17 july 2006 java tsunami 1 the 17 july 2006 magnitude mw 7 8 earthquake off the south coast of western java indonesia generated a tsunami that effected over 300 km of coastline and killed more than 600 people with locally focused runup heights exceeding 20 m this slow earthquake was hardly felt on java and wind waves breaking masked any preceding withdrawal of the water from the shoreline making this tsunami difficult to detect before impact an international tsunami survey team was deployed within one week and the investigation covered more than 600 km of coastline measured tsunami heights and run up distributions were uniform at 5 to 7 m along 200 km of coast however there was a pronounced peak on the south coast of nusa kambangan where the tsunami impact carved a sharp trimline in a forest at elevations up to 21 m and 1 km inland local flow depth exceeded 8 m along the elevated coastal plain between the beach and the hill slope we infer that the focused tsunami and runup heights on the island suggest a possible local submarine slump or mass movement

provenance environmental and paleogeographic controls on sandstone composition in an incised valley system the eocene la meseta formation seymour island antarctica abstract the eocene la meseta formation is the youngest exposed unit of the back arc james ross basin antarctic peninsula cropping out in seymour marambio island the formation comprises 720 m of clastic sedimentary rocks of deltaic estuarine and shallow marine origin it was subdivided into six unconformity based units valle de las focas acantilados campamento cucullaea i cucullaea ii and submeseta allomembers grouped into three main facies associations facies association i represents valley confined deposition in a progradational aggradational tide dominated and wave influenced delta front delta plain environment facies association ii includes tidal channels mixed tidal flats tidal inlets and deltas washover and beach environments facies association iii represents nonconfined tide and storm influenced nearshore environments la meseta formation sandstones are quartzofeldspathic with some hybrid arenites glauconite and carbonate bioclasts rich sandstone detrital modes are subdivided into two distinctive petrofacies the low quartz petrofacies petrofacies i q 12 interpreted to retain the original provenance signal and the high quartz petrofacies petrofacies ii q 55 and l 1 4 is clearly dominated by volcanic derived clasts it developed at times of high sea level and or during later stages of the valley fill when an energy fence at the shoreline prevented delivery of sediment from the antarctic peninsula thus enhancing the relative participation of local volcanic sources

ancestral heritage saves tribes during 1 april 2007 solomon islands tsunami 1 the 1 april 2007 magnitude ms 8 1 earthquake off the new georgia group in the solomon islands generated a tsunami that killed 52 with locally focused run up heights of 12 m local flow depths of 5 m as well as tectonic uplift up to 3 6 m and subsidence down to 1 5 m a reconnaissance team deployed within one week investigated 65 coastal settlements on 13 remote islands the ancestral heritage run to high ground after an earthquake passed on to younger generations by survivors of smaller historic tsunamis triggered an immediate spontaneous self evacuation containing the death toll

sandstone petrology and provenance of the siwalik group northwestern pakistan and western southeastern nepal abstract the siwalik group consists of a neogene sedimentary succession 5 8 km thick deposited as the himalayan foreland basin developed following collision between the indian and eurasian continents it consists of fluvial deposits composed of shale siltstone and sandstone in the lower part and thick sandstone and conglomerate in the upper part this paper presents new petrologic data on the sandstone composition of two coeval petrofacies of siwalik group in two areas the potwar plateau of northwestern pakistan and the surai khola and bakiya khola localities of western and southeastern nepal in both regions detrital modes reflect a collisional orogen provenance petrologic parameters indicate derivation from mid crustal rocks and overlying sedimentary strata ascribed to different tectonostratigraphic units of the high himalaya and tibetan zone the siwalik sandstones of the potwar plateau nw pakistan are composed of low to medium grade metamorphic and sedimentary detritus and subordinately of ophiolitic and volcanic detritus abundant metamorphic detritus consists of phyllite fine grained schist lithics and coarse grained gneiss derived from the high and or lesser himalaya sedimentary detritus is represented by abundant limestone radiolarian chert siltstone shale very fine grained quartzarenite and other sandstone grains the siliciclastic grains probably were eroded from older terrigenous sequences belonging to the tethys himalayan and lesser himalayan zones uplifted during the india eurasia collision ophiolitic volcanic lithic grains and radiolarian chert reflect a provenance from the indus suture and tran himalayan belt the sandstones of western and southeastern nepal surai khola and bakiya khola sections have higher quartz and lower feldspar contents than those of northwestern pakistan and contain sedimentaclastic western nepal and metamorphiclastic sandstones southeastern nepal comparison of the data presented here with previous work on pre and post siwalik sandstones of the himalaya range and of the remnant ocean basins along both sides of the indian peninsula also derived from the himalayan suture belt suggests abundant quartzolithic detritus from the eocene to the present varying proportions of lithic populations in time are related to rapid uplift of the himalayas and intense unroofing of sedimentary metasedimentary and deeper terranes

the energetic 2010 mw 7 1 solomon islands tsunami earthquake summary on 2010 january 3 a moment magnitude mw 7 1 earthquake struck the solomon islands very near the san cristobal trench causing extensive landslides and surprisingly large tsunami waves because of the unique proximity of islands to the trench 20 km and earthquake a post seismic survey successfully identified unexpected widespread coseismic subsidence towards the trench up to 80 cm with no discernable post seismic deformation approximately 1000 km from the earthquake ocean bottom pressure sensors measured 1 2 cm open ocean tsunami waves though spatially limited the local tsunami wave heights up to 7 m were comparable to the much larger adjacent 2007 mw 8 1 earthquake the seismically determined focal mechanism broad scale subsidence tsunami amplitude and open ocean wave heights are all explained by an extremely shallow low angle thrust adjacent to the impinging subduction of the two seamounts near the trench this event belongs to a potentially new class of shallow tsunami earthquakes that is not identified as deficient in radiated seismic energy

twenty five years of progress in the science of geological tsunamis following the 1992 nicaragua and flores events we review a set of 47 tsunamis of geological origin triggered by earthquakes landslides or volcanoes which have occurred over the past 25 years and provided significant new insight into theoretical experimental field or societal aspects of tsunami science among the principal developments in our command of various aspects of tsunamis we earmark the development of the w phase inversion for the low frequency moment tensor of the parent earthquake the abandonment of the concept of a maximum earthquake magnitude for a given subduction zone controlled by simple plate properties the development and implementation of computer codes simulating the interaction of tsunamis with initially dry land at beaches thus introducing a quantitative component to realistic tsunami warning procedures and the recent in situ investigation of current velocities in addition to the field of surface displacements during the interaction of tsunamis with harbors continued research remains warranted notably in the field of the real time identification of tsunami earthquakes whose tsunamis are larger than expected from their seismic magnitudes especially conventional ones the recent tragedy during the 2018 krakatau flank collapse along a scenario which had been quantitatively forecast also emphasizes the need for a continued effort in the education of the populations at risk

interpretation of neovolcanic versus palaeovolcanic sand grains an example from miocene deep marine sandstone of the topanga group southern california despite abundant data on volcaniclastic sand stone the compositional spatial and temporal distribution of volcanic detritus within the sedimentary record is poorly documented one of the most intricate tasks in optical analysis of sand stone containing volcanic particles is to distinguish grains derived by erosion of ancient volcanic rocks i e palaeovolcanic noncoeval grains from grains generated by active volcanism subaqueous and or subaerial during sedimentation neovolcanic coeval grains deep marine volcaniclastic sandstones of the middle topanga group of southern california are interstratified with 3000 m thick volcanic deposits both subaqueous and subaerial lava and pyroclastic rocks ranging from basalt andesite to dacite these rocks overlie quartzofeldspathic sandstones petrofacies 1 of the lower topanga group derived from deep erosion of a mesozoic magmatic arc changes in sandstone composition in the middle topanga group provide an example of the influence of coeval volcanism on deep marine sedimentation volcaniclastic strata were deposited in deep marine portions of a turbidite complex volcaniclastic apron built onto a succession of intrabasinal lava flows and on the steep flanks of subaerially emplaced lava flows and pyroclastic rocks distinctive petrofacies 2 5 directly overlying basalt and basaltic andesite lava flows petrofacies 2 is a pure volcanolithic sandstone including vitric microlitic and lathwork volcanic grains and neovolcanic crystals plagioclase pyroxene and olivine the abundance of quenched glass palagonite fragments suggests a subaqueous neovolcanic provenance whereas sandstones including andesite and minor basalt grains suggest subaerial neovolcanic provenance this petrofacies probably was deposited during syneruptive periods testifying to provenance from both intrabasinal and extrabasinal volcanic events deposited during intereruptive periods impure volcanolithic petrofacies 3 includes both neovolcanic 85 and older detritus derived from plutonic metamorphic and palaeovolcanic rocks during post eruptive periods the overlying quartzofeldspathic petrofacies 4 and 5 testify to progressive decrease of neovolcanic detritus 48 14 and increase of plutonic metamorphic and palaeovolcanic detritus the upper topanga group calabasas formation conformably overlying the middle unit has dominantly plutoniclastic sandstone petrofacies 6 neovolcanic detritus is drastically reduced 4 whereas palaeovolcanic detritus is similar to percentages of the lower topanga group petrofacies 1 the middle topanga group sandstones are vertically organized into four

tsunami simulations for regional sources in the south china and adjoining seas we present 14 scenarios of potential tsunamis in the south china sea and its adjoining basins the sulu and sulawezi seas the sources consist of earthquake dislocations inspired by the the study of historical events either recorded since 1900 or described in historical documents going back to 1604 we consider worst case scenarios where the size of the earthquake is not limited by the largest known event but merely by the dimension of the basin over which a coherent fault may propagate while such scenarios are arguably improbable they may not be impossible and as such must be examined for each scenario we present a simulation of the tsunami s propagation in the marine basin exclusive of its interaction with the coastline our results show that the south china sulu and sulawezi seas make up three largely independent basins where tsunamis generated in one basin do not leak into another similarly the sunda arc provides an efficient barrier to tsunamis originating in the indian ocean furthermore the shallow continental shelves in the java sea the gulf of thailand and the western part of the south china sea significantly dampen the amplitude of the waves the eastern shores of the malay peninsula are threatened only by the greatest and most improbable of our sources a mega earthquake rupturing all of the luzon trench we also consider two models of underwater landslides which can be triggered by smaller events even in an intraplate setting these sources for which there is both historical and geological evidence could pose a significant threat to all shorelines in the region including the malay peninsula

source process of the great 1971 solomon islands doublet abstract large underthrusting earthquakes in the solomon islands tend to occur as multiplets separated by a few hours to several days in time and 30 100 km in space the largest sequence a doublet on july 14 1971 m w 8 0 and july 26 1971 m w 8 1 is particularly unusual in that it occured at the junction of two trenches with the july 14 event in the solomon islands trench preceding the july 26 rupture in the new britain trench the location and large moment release of this doublet as well as an incompatibility of published body wave and surface wave focal mechanisms for the july 14 event motivated a detailed study of the source process of the 1971 sequence to satisfy both the surface wave and body wave data we explored the possibility of a change in the faulting geometry during rupture for the july 14 event a fault model that changes orientation from a northwest southeast striking shallow dipping plane similar to the mechanisms of neighboring underthrusting events in the solomon islands trench to a more north south striking plane 70 s after rupture initiation is consistent with the observed rayleigh and love wave amplitude patterns this change in mechanism is suggested by systematic variations in the mechanisms of smaller earthquakes near the cusp in the solomon islands plate a simultaneous inversion of wwssn p wave seismograms for the time location seismic moment and focal mechanism of individual subevents gives results in agreement with the surface wave model although the precise change in mechanism is not well resolved the spatiotemporal distribution of subevents reveals two major pulses of moment release the first occurred on the initial fault near the epicenter at the origin time of the earthquake the second occurred on the north south striking fault 50 70 km northwest of the epicenter 70 s after the origin time the change in mechanism appears to reflect contortion of the slab near the trench junction inversion of wwssn p wave seismograms for the rupture history of the july 26 event reveals a westerly propagating rupture extending 60 km along the new britain trench for both of the 1971 earthquakes regions of high moment release are located in the vicinity of the solomon islands new britain trench junction contortion of the subducting lithosphere as it bends around the arc arc junction may have enhanced the degree of mechanical coupling between the subducting and overriding plates concentrating stress in this region and in turn promoting efficient triggering across the trench junction

the 15 august 2007 peru tsunami runup observations and modeling 1 on 15 august 2007 an earthquake with moment magnitude mw of 8 0 centered off the coast of central peru generated a tsunami with locally focused runup heights of up to10 m a reconnaissance team was deployed two weeks after the event and investigated the tsunami effects at 51 sites three tsunami fatalities were reported south of the paracas peninsula in a sparsely populated desert area where the largest tsunami runup heights were measured numerical modeling of the earthquake source and tsunami suggest that a region of high slip near the coastline was primarily responsible for the extreme runup heights the town of pisco was spared by the paracas peninsula which blocked tsunami waves from propagating northward from the high slip region the coast of peru has experienced numerous deadly and destructive tsunamis throughout history which highlights the importance of ongoing tsunami awareness and education efforts to ensure successful self evacuation

mechanical origin of power law scaling in fault zone rock 1 a nearest neighbor fragmentation model previously developed to explain observations of power law particle distributions in 3d with mass dimension d 3 2 6 d 2 2 6 in 2d section in low strain fault gouge and breccia is extended to the case of large strains to explain recent observations of d 3 3 0 d 2 2 0 in 2d section in the highly strained cores of many exhumed fault zones at low strains the elimination of same sized nearest neighbors has been shown to produce a power law distribution which is characterized by a mass dimension near d 3 2 6 with increasing shear strain these isolated same size neighbors can collide in which case one of them fractures the probability of two same size neighbors colliding and fragmenting in a simple shear flow is a function of the size and density of the two particles only for a power law distribution with d 3 3 0 is this collision probability independent of the size of the particles citation sammis

source spectrum for the algerian tsunami of 21 may 2003 estimated from coastal tide gauge data 1 on 21 may 2003 a submarine earthquake occurred near algiers producing a tsunami that propagated northward and reached the balearic islands and the levantine coast of the iberian peninsula within an hour despite that the generated tsunami was moderate sea level variations inside certain harbors at the balearic islands were significant producing severe damage to moored boats available tsunami records in the affected harbors are examined to estimate amplifications factors of arriving waves and spectral characteristics of the source comparison between background and tsunami oscillations at various sites allowed separation of the tsunami source properties from local topographic effects the fundamental period of the reconstructed source spectrum is 21 min which is in close agreement with that found by alasset et al 2006 based on modeling the tsunami initiation

a bayesian rupture model of the 2007 mw 8 1 solomon islands earthquake in southwest pacific with coral reef displacement measurements abstract on 1st april 2007 a mw 8 1 megathrust earthquake occurred in the western solomon islands of the southwest pacific and generated a regional tsunami with run up heights of up to 12 m a bayesian inversion model is constructed to derive fault dip angle and cumulative co seismic and early post seismic slip using coral reef displacement measurements in which both data misfit and moment magnitude are used as constraints results show three shallow high slip patches concentrated along the trench from west of ranongga island to rendova island on a fault plane dipping 20 and a maximum dip slip of 11 6 m beneath ranongga island considerable subsidence on simbo island outboard of the trench on the subducting plate is not well explained with this model but may be related to the effects of afterslip and or simbo island s location near the triple junction among the australia woodlark and pacific plates

source models and near field impact of the 1 april 2007 solomon islands tsunami within weeks of the solomon islands earthquake of 1 april 2007 international tsunami survey teams discovered important biomarkers of crust rupture and tsunami heights along the islands coastlines deep ocean tsunameters recorded the tsunami waves of this event enabling a real time inversion of the tsunami source and model evaluation of near field tsunami impact the survey measurements provide valuable datasets for further confirmation of the tsunami source of the 1 april 2007 solomon earthquake these survey results also aided investigation of the correlation between sources determined by use of tsunameter records and those derived from seismometer records or crust rupture measurements in this study to assess the near field tsunami impact we developed tsunami inundation models for the solomon islands including tsunami waveforms co seismic land level changes and tsunami height distributions on individual islands compared with seismic derived tsunami sources modeling results based on the tsunameter derived tsunami sources were a good match with field survey measurements these results highlight the accuracy and efficiency of the tsunameter derived tsunami source in modeling the near field tsunami impact along a complex archipelago we show that the source models although derived by use of different methods are all suited to initiation of inundation models developed for solomon islands as these source models become available in real time or near real time they can be implemented immediately in the inundation models to provide rapid guidance on tsunami hazard assessment focused search and rescue operations and post event recovery and reconstruction

tsunami sediments and their foraminiferal assemblages abstract tsunami hazard assessment begins with a compilation of past events that have affected a specific location given the inherent limitations of historical archives the geological record has the potential to provide an independent dataset useful for establishing a richer chronologically deeper time series of past events recent geological studies of tsunami are helping to improve our understanding of the nature and character of tsunami sediments wherever possible geologists should be working to improve the research tool kit available to identify past tsunami events marine foraminifera single celled heterotrophic protists have often been reported as present within tsunami deposited sediments but in reality little information about environmental conditions and by analogy the tsunami that deposited them has been reported even though foraminifera have an enormous capacity to provide meaningful palaeo environmental data here we review what foraminifera are describe their basic form and significance summarise where they have been reported in tsunami sediments and identify what can be learnt from them we review the gaps in our understanding and make recommendations to assist researchers who examine foraminiferal assemblages in order to enhance their use within tsunami geology

triassic redbeds in the malaguide complex betic cordillera spain petrography geochemistry and geodynamic implications abstract sandstone petrography and mudstone mineralogy and geochemistry of triassic mudstones and sandstones from continental redbeds of the malaguide complex betic cordillera southern spain provide useful information on provenance palaeoclimate and geodynamics during the early stages of the pangea break up and on their diagenetic evolution the sandstones are quartzarenites to sub litharenites with minor lithic fragments and rare feldspars the mudstone samples show a paas like elemental distribution the samples likely record recycling processes from their metasedimentary basement rocks that significantly affected the weathering indices and monitors cumulative effects including a first cycle of weathering at the source rocks sandstone composition and chemical mineralogical features of mudstones record a provenance derived from continental block and recycled orogen that were weathered under warm and episodically wet climate source areas were located towards the east of the present day malaguide outcrops and were formed by fairly silicic rock types made up mainly of palaezoic metasedimentary rocks similar to those of the paleozoic underlying series with subordinate contributions from magmatic metamorphic sources and a rare supply from mafic metavolcanic rocks clay mineral distribution of mudstones is dominated by illite and illite smectite mixed layer that result from differences in provenance weathering and burial temperature history illite crystallinity values illitization of kaolinite occurrence of typical authigenic minerals and apatite fission track studies coupled with a subsidence analysis of the whole malaguide succession suggest burial depths of at least 4 6 km with temperatures of 140 160 c typical of the burial diagenetic stage and confirm the middle miocene exhumation of the betic internal domain tectonic stack topped by the malaguide complex

detrital modes of the pyeongan supergroup late carboniferous early triassic sandstones in the samcheog coalfield korea implications for provenance and tectonic setting abstract medium to coarse sandstones of the carboniferous to early triassic pyeongan supergroup in the samcheog coalfield korea were studied to infer the provenance and tectonic settings of the source areas sandstone detrital modes change upwards stratigraphically sandstone types from the manhang to dosagog formations low to middle in the sequence are quartzarenite and sublitharenite to litharenite whereas sandstones of the gohan and donggo formations high in the sequence are feldspathic litharenite and arkose respectively using various ternary diagrams the provenance of the manhang to gohan formations is suggested to be a recycled orogen setting some gohan formation sandstones plot within the arc related setting field and the donggo formation sandstones plot within both continental block and recycled orogen fields results of quartz grain petrography are consistent with those of detrital modes quartz in sandstones of all units except the donggo formation indicates derivation from low rank metamorphic sources quartz in donggo sandstones was derived from medium to high rank metamorphic and plutonic source rocks considering the sandstone composition and palaeocurrent data the pyeongan supergroup probably was deposited in a molasse foreland basin and was derived from a synbasinal orogenic belt probably the akiyoshi orogen located in southwest japan

sedimentary evolution of the mesozoic continental redbeds using geochemical and mineralogical tools the case of upper triassic to lowermost jurassic monte di gioiosa mudrocks sicily southern italy the continental redbeds from the internal domains of the central western mediterranean chains have an important role in the palaeogeographic and palaeotectonic reconstructions of the alpine circum mediterranean orogen evolution since these redbeds mark the triassic jurassic rift valley stage of tethyan rifting the composition and the sedimentary evolution of the middle triassic to lowermost jurassic continental redbeds of the san marco d alunzio unit peloritani mountains southern italy based on mineralogical and chemical analyses suggests that the studied mudrock sediments share common features with continental redbeds that constitute the internal domains of the alpine mediterranean chains phyllosilicates are the main components in the mudrocks the 10 a minerals illite and micas the i s mixed layers and kaolinite are the most abundant phyllosilicates the amount of illitic layers in i s mixed layers coupled with the illite crystallinity values ic are typical of high degree of diagenesis corresponding to a lithostatic tectonic loading of about 4 5 km the mineralogical assemblage coupled with the a cn k plot suggest post depositional k enrichments palaeoweathering proxies pia and ciw record intense weathering at the source area further the studied sediments are affected by reworking and recycling processes and as consequence it is likely these proxies monitor cumulative effect of weathering the climate in the early jurassic favoured recycling and weathering occurred under hot episodically humid climate with a prolonged dry season the source area is the low grade paleozoic metasedimentary basement mafic supply is minor but not negligible as suggested by provenance proxies

inertinite rich tertiary coals from the zeya bureya basin far eastern russia selected tertiary coals from the zeya buryea basin far eastern russia were investigated for aspects of their coal type rank depositional environment and post depositional history the coals have been examined in outcrop lithotype logging microscopically maceral reflectance and fluorescence and geochemically proximate analysis two laterally extensive coal bearing horizons occur one of palaeocene age and the other of early miocene age the palaeocene coals were investigated in active open cut mines at raichikhinsk and yerkovtsi and the early miocene deposit in an abandoned open cut mine at cergeyevka palaeocene coals at raichikhinsk and yerkovtsi were indistinguishable from each other macroscopically microscopically and geochemically the deposits were sufficiently coalified that brightness logging could be undertaken dull coals with numerous fusainous wisps were dominant four dulling up sequences which represent stacked peat deposits were observed at raichikhinsk at yerkovtsi only a small section of the middle of the seam which was mostly dull and muddy coal was investigated petrographically these coals were dominated by inertinite group macerals which is unusual in non gondwanan coals and rare in the tertiary rank classification was problematic with volatile matter vm content of vitrain daf macroscopic appearance and microscopic textures suggesting subbituminous b rank but carbon content moisture content and specific energy indicating a lignite rank notwithstanding complications of rank estimates of the maximum range burial depths were calculated taking the vm daf content of vitrain as 48 burial depth estimates range from 900 m for a high geothermal gradient and long heating time to a maximum of 3300 m for a low geothermal gradient and short heating time these estimates are maxima as the coal rank may be lower than implied by the vm the cergeyevka deposit is a soft brown coal limited sampling of the upper most portion indicated a high moisture content 75 daf and an unusual hydrogen rich geochemistry lack of identifiable liptinites using either reflected light or fluorescence microscopy suggested a significant bituminite component otherwise the coals appear to be typical for the tertiary an estimate of 125 m maximum burial depth was obtained using the bed moisture content of the coal which is around the present burial depth comparison of present day thicknesses with inferred burial depths suggests that at least 500 m of section is missing between the palaeocene coals and the early miocene coals palaeoenvironmental considerations suggest that fire played a significant role in the accumulation of the peats at raichikhinsk and yerkovtsi at cergeyevka peat accumulation ended by drowning of the mire two tuff beds were recognised within the seam at raichikhinsk and one in the seam at yerkovtsi correlation of the tuff beds is uncertain but they should prove useful in regional coal seam correlation and interpreting coal depositional environments geochemical analysis by xrf was complicated by high loss on ignition loi values despite extensive alteration an acid igneous source is implied from the presence of free quartz and tio2 al2o3 ratios of 0 02 to 0 05