penultimate predecessors of the 2004 indian ocean tsunami in aceh sumatra stratigraphic archeological and historical evidence we present stratigraphic archeological and historical evidence for two closely timed predecessors of the giant 2004 tsunami on the northern coast of aceh northern sumatra this is the first direct evidence that a tsunami played a role in a fifteenth century cultural hiatus along the northern sumatran portion of the maritime silk route one seacliff exposure on the eastern side of the lambaro headlands reveals two beds of tsunamigenic coral rubble within a small alluvial fan radiocarbon and uranium thorium disequilibrium dates indicate emplacement of the coral rubble after 1344 3 c e another seacliff exposure on the western side of the peninsula contains evidence of nearly continuous settlement from 1240 c e to soon after 1366 3 c e terminated by tsunami destruction at both sites the tsunamis are likely coincident with sudden uplift of coral reefs above the sunda megathrust 1394 2 c e evidence for which has been published previously the tsunami or tsunami pair appears to have destroyed a vibrant port community and led to the temporary recentering of marine trade dominance to more protected locations farther east the reestablishment of vibrant communities along the devastated coast by about 1500 ce set the stage for the 2004 disaster

typhoon haiyan overwash sediments from leyte gulf coastlines show local spatial variations with hybrid storm and tsunami signatures abstract marine inundation associated with the 5 to 8 m storm surge of typhoon haiyan in 2013 left overwash sediments inland on the coastal plains of the northwestern shores of leyte gulf philippines the haiyan overwash deposit provides a modern sedimentary record of storm surge deposition from a category 5 landfalling typhoon we studied overwash sediments at two locations that experienced similar storm surge conditions but represent contrasting sedimentological regimes namely a siliciclastic coast and a mixed siliciclastic carbonate coast the contrasting local geology is significantly reflected in the differences in sediment grain size composition and sorting at the two sites the haiyan overwash sediments are predominantly sand and silt and can be traced up to 1 6 km inland extending farther beyond the previously reported

hurricane records on the south carolina coast can they be detected in the sediment record abstract more than 40 short cores were collected from 10 localities in the myrtle beach to mcclellandville coastline of south carolina the localities were selected on the basis of whether or not they should have a well preserved record of recent hurricanes most notably hugo which occurred in september 1989 of the 40 cores collected results from two sites are presented here as examples price s inlet a non tidal intra beach ridge area which was directly in the path of the eyewall of hugo and sandpiper pond which is a coastal non tidal pond near murrells inlet about 50 75 km north of where the main landfall of hurricane hugo but still in the area of high storm surge these cores were analyzed for percentage organic carbon visual observations x rays and microfossils the microfossils were used to differentiate marine non marine sequences in the non tidal inlets and identify reworked sediments by means of displaced benthic foraminifera cores were dated using pb 210 techniques that provide resolution for the last 100 yr in price s inlet the hugo effect was most pronounced with an 8 cm thick sand layer containing many nearshore foraminifera showing transport from offshore in sandpiper pond we could see the trace of hugo from the offshore foraminifera contained in sediments sandwiched between the freshwater intervals both before and after hugo however there was little detectable trace in the x rays or sedimentology of this core to indicate a storm event hence we can recognize a range of responses for hurricanes in the form of different types of sediment layers and microfossil assemblages in these non tidal areas depending on where the impact point is on the coast here we are able to distinguish at least two types of signals from the same storm which has significant implications for detecting these events in the pre historic record and determining their paleo periodicity

are inundation limit and maximum extent of sand useful for differentiating tsunamis and storms an example from sediment transport simulations on the sendai plain japan we examined the quantitative difference in the distribution of tsunami and storm deposits based on numerical simulations of inundation and sediment transport due to tsunami and storm events on the sendai plain japan the calculated distance from the shoreline inundated by the 2011 tohoku oki tsunami was smaller than that inundated by storm surges from hypothetical typhoon events previous studies have assumed that deposits observed farther inland than the possible inundation limit of storm waves and storm surge were tsunami deposits however confirming only the extent of inundation is insufficient to distinguish tsunami and storm deposits because the inundation limit of storm surges may be farther inland than that of tsunamis in the case of gently sloping coastal topography such as on the sendai plain in other locations where coastal topography is steep the maximum inland inundation extent of storm surges may be only several hundred meters so marine sourced deposits that are distributed several km inland can be identified as tsunami deposits by default over both gentle and steep slopes another difference between tsunami and storm deposits is the total volume deposited as flow speed over land during a tsunami is faster than during a storm surge therefore the total deposit volume could also be a useful proxy to differentiate tsunami and storm deposits

assessing surficial foraminiferal distributions as an overwash indicator in sur lagoon sultanate of oman abstract the identification of tsunami and storm deposits in arid coastal environments can be problematic as overwash sediments may not show significant contrasting lithologic characters with lagoonal sediments in this study foraminifera were evaluated as an overwash indicator in a small 12 km2 intertidal lagoon located at sur in the sultanate of oman the lagoon is shallow

sediments deposited by the 2004 indian ocean tsunami along the malaysia thailand peninsula stratigraphy grain size distribution and foraminiferal assemblages of pre tsunami and tsunami sediment from the indian ocean tsunami at five sites along the malaysia thailand peninsula were analyzed to gain information on tsunami sediment source and deposition style between three and five stratigraphic units were identified at each site and contained between one and three fining upward sequences reflecting waning flow or pre backwash deposition coarser sand layers reflecting uprush high energy flow separated the fining upward sequences with the exception of one site sungai burong which contained a coarsening upward sequence all contacts between the pre tsunami and tsunami sediment were sharp or erosional medium and coarse sand dominated all of the tsunami sediment deposits and often contained shell fragments foraminiferal assemblages were able to differentiate pre tsunami sediment from tsunami sediment where no lithological or grain size distribution change was evident between two and four foraminiferal zones were identified at each of the five sites and provided estimates of sediment source and wave characteristics

recognition of diagnostic criteria for recent and paleo tsunami sediments from sri lanka uncontaminated sediment from the december 26 2004 tsunami in southern sri lanka was collected from a previously empty arrack bottle stacked in a plastic case at an elevation of about 5 m above mean sea level and from several other localities the sediments were analysed for grain size distribution sediment petrography and microfossil assemblages and were compared with storm surge sediment and nearshore sediment the undiluted tsunami sediment is a brownish silty fine sand it is characterized by a particular grain size distribution and an assemblage of planktonic benthic microfossils consisting of foraminifera radiolarians and spicules storm surge and nearshore sediments are better sorted have fewer microfossils more rounded quartz grains and a higher proportion of heavy minerals influenced by references in sri lankan ancient texts to past tsunamis we searched for paleo tsunami sediments in potential locations such as the coastal depressions in borehole samples and well cuttings from soil profiles in the coastal village of peraliya we were able to recognize two paleo tsunami horizons at 30 and 75 cm below the present ground surface each consisting of brownish silty fine sand that remarkably resembled the recently deposited undiluted tsunami sediment

mid to late holocene marine inundations inferred from coastal deposits facing the nankai trough in nankoku kochi prefecture southern japan this study investigates the holocene sedimentary history of a small coastal lowland in nankoku kochi prefecture on the coast of southern japan facing the nankai trough the sedimentary fill of th

sedimentary and foraminiferal evidence of the 2011 tōhoku oki tsunami on the sendai coastal plain japan abstract the 2011 t hoku oki megathrust earthquake mw 9 0 generated a tsunami that reached the sendai coastal plain with flow heights of 2 to 11 m above tp tokyo peil we examined the tsunami deposit exposed in 14 shallow trenches along a 4 5 km transect perpendicular to the coast we primarily document the stratigraphical sedimentological foraminiferal and geochemical characteristics of the t hoku oki tsunami deposit and perform a preliminary comparison with sediments deposited by the j gan tsunami of a d 869 in the coastal forest and rice fields inundated by the t hoku oki tsunami a poorly sorted dark brown soil is buried by a poorly sorted brown medium grained sand deposit in some trenches located more than 1 2 km inland the sand is capped by a thin muddy sand layer the tsunami deposit although highly variable in thickness is generally thickest 25 cm near the coastal dune and thins to less than 5 mm at 4 5 km inland the tsunami deposit was discriminated from the underlying soil by the appearance of recent and fossil foraminifera and a pronounced increase in grain size that fined upward and landward the recent foraminifera preserved in the sandy facies of the deposit are rare and showed evidence of prolonged subaerial exposure e g pitting corrosion fragmentation recent foraminifera likely originated from coastal dune and beach sediments that were breached by the tsunami calcified and sediment in filled fossil foraminifera are abundant and were eroded from sedimentary units and transported by fluvial or wave activity to sendai bay trends associated with test size e g decreasing concentration of large test sizes with distance inland are in agreement with grain size data at two locations a decrease in total organic carbon and an increase in 13c were found in the tsunami sand compared with the underlying soil supporting a beach to intertidal origin for the upper unit

tropical cyclone wind speed constraints from resultant storm surge deposition a 2500 year reconstruction of hurricane activity from st marks fl 1 recent work suggests that the patterns of intense category 3 on the saffir simpson scale hurricane strikes over the last few millennia might differ from that of overall hurricane activity during this period prior studies typically rely on assigning a threshold storm intensity required to produce a sedimentological overwash signal at a particular coastal site based on historical analogs here we improve on this approach by presenting a new inverse model technique that constrains the most likely wind speeds required to transport the maximum grain size within resultant storm deposits as a case study the technique is applied to event layers observed in sediments collected from a coastal sinkhole in northwestern florida we find that 1 simulated wind speeds for modern deposits are consistent with the intensities for historical hurricanes affecting the site 2 all deposits throughout the 2500 year record are capable of being produced by hurricanes and 3 a period of increased intense hurricane frequency is observed between 1700 and 600 years b p and decreased intense storm frequency is observed from 2500 to 1700 and 600 years b p to the present this is consistent with prior reconstructions from nearby sites changes in the frequency of intense hurricane strikes may be related to the degree of penetration of the loop current in the gulf of mexico

lake sediment record of late holocene hurricane activities from coastal alabama coastal lake sediments contain a stratigraphically and chronologically distinct record of major hurricane strikes during late holocene time frederic a category 3 hurricane that struck the alabama coast on the gulf of mexico in 1979 left a distinct sand layer in the nearshore sediments of lake shelby as a result of storm tide overwash of beaches and dunes sediment cores taken from the center of lake shelby contain multiple sand layers suggesting that major hurricanes of category 4 or 5 intensity directly struck the alabama coast at ca 3 2 3 0 2 6 2 2 1 4 and 0 8 ka 14 c yr with an average recurrence interval of 600 yr the alabama coast is likely to be struck by a category 4 or 5 hurricane within the next century

micropaleontology of the 2013 typhoon haiyan overwash sediments from the leyte gulf philippines abstract coastal geologic records allow for the assessment of long term patterns of tropical cyclone variability however the accuracy of geologic reconstructions of tropical cyclones is limited by the lack of modern analogues we describe the microfossil foraminifera and testate amoebae assemblages contained within overwash sediments deposited by typhoon haiyan when it made landfall on the islands of leyte and samar in the philippines on 7 november 2013 as a category 5 super typhoon the overwash sediments were transported up to 1 7 km inland at four study sites the sediments consisted of light brown medium sand in a layer

detection of creep along the philippine fault first results of geodetic measurements on leyte island central philippine geodetic trilateration gps measurements were acquired from experiments conducted in 1991 and 1993 in the central part of the philippine fault on leyte island displacement vectors deduced from two least squares adjustments indicate a mean slip rate of 26 10 mm yr at an azimuth of about n130 e these values are consistent with the tectonic and kinematic data our results indicate that the displacements are 1 almost parallel to the philippine fault and 2 related to creep along the fault because no moderate seismic events occurred between the two observation epochs

from in situ coal to fly ash a study of coal mines and power plants from indiana abstract this paper presents data on the properties of coal and fly ash from two coal mines and two power plants that burn single source coal from two mines in indiana one mine is in the low sulfur 5 springfield coal member of the petersburg formation pennsylvanian both seams have comparable ash contents 11 coals sampled at the mines both raw and washed fractions were analyzed for proximate ultimate sulfur forms heating value major oxides trace elements and petrographic composition the properties of fly ash from these coals reflect the properties of the feed coal as well as local combustion and post combustion conditions sulfur and spinel content and as pb and zn concentrations of the fly ash are the parameters that most closely reflect the properties of the source coal

studies on settling traction and entrainment of larger benthic foraminiferal tests implications for accumulation in shallow marine sediments settling and traction velocities were measured on optimally preserved tests of larger foraminifera using a settling tube and flume tank within larger foraminifera with porcelaneous tests the peneroplids peneroplis antillarum p planatus p pertusus and dendritina cf d zhengae are distinguished by low test densities ca 1 2 that do not change with growth buoyancy is high because of low reynolds numbers and increases in large individuals because of the allometric change of test shape the fusiform alveolinella quoyi with test densities ca 1 6 is characterized by high reynolds numbers inducing the weakest buoyancy within porcelaneous larger foraminifera the highest buoyancy was recorded for the three soritids parasorites orbitolitoides sorites orbiculus and amphisorus hemprichii because of their low test densities ca 1 25 and the extremely flat biconcave plate like shape flat tests however reduce traction and entrainment from smooth surfaces within hyaline larger foraminiferat the amphisteginids show thick lenticular amphistegina lobifera a radiata to thin lenticular tests a bicirculata a papillosa influencing buoyancy here high test densities ca 1 8 decrease with growth in a lobifera a lessonii and a bicirculata and remain constant in a radiata and a papillosa minimum velocities required for entrainment are lower for thick lenticular tests and higher for thin lenticular tests test densities remain constant with growth in the calcarinid baculogypsina sphaerulata 1 78 and decrease slightly in calcarina gaudichaudii and neorotalia calcar starting at 1 85 all living under extreme hydrodynamic conditions density decreases the most in baculogypsinoides spinosus starting at 1 8 resulting in higher buoyancy through low reynolds numbers traction is promoted in spherical tests of baculogypsina and baculogypsinoides within nummulitids the thick lenticular palaeonummulites venosus test density decreasing with size starting at 1 78 is less buoyant expressed in high reynolds numbers but easily entrained thick lenticular juveniles and extremely flat adults distinguish operculinella cumingii heterostegina depressa and the giant cycloclypeus carpenteri test densities increase during growth starting from ca 1 6 and attaining a maximum of 1 8 buoyancy is low in small tests and high in large tests while entrainment velocities are reduced as the tests flatten high buoyancy is also a characteristic of the entirely flat tests in operculina ammonoides from deeper regions and planostegina operculinoides which is expressed in the lowest reynolds numbers within larger foraminifera

predecessors to the 2009 south pacific tsunami in the wallis and futuna archipelago abstract multi proxy studies of trench sediments from futuna island in the wallis and futuna archipelago have produced a record of two palaeotsunamis dated to around 1860 2000 bp and c 470 bp one of the most useful proxies in this study has been the archaeological data associated with occupations that immediately underlie the deposits associated with both palaeotsunamis the reworking of the archaeological material into the palaeotsunami deposits and the additional chronological control provided by artefacts have added value to interpretations based upon more conventional earth science proxies the identification of tsunamigenic sources for these events is tentative and based upon known potential sources based upon a comparison between the effects of the 2009 south pacific tsunami and those recorded in the trenches event 1 1860 2000 bp appears most likely to be associated with a large tsunami sourced from the tonga kermadec trench region there are only rare contemporaneous events reported from around the region although this appears to be largely due to a lack of similar research as opposed to a lack of evidence event 2 c 470 bp is markedly larger than event 1 with sedimentary evidence indicating significant inland inundation and runup around the entire island there are several lines of evidence for a contemporaneous event in the south pacific around 470 bp although much of this needs further verification determining a source for this event is problematic because it must take in to account the regional signal and the significant impacts recorded on futuna we propose that the source for this younger event was either a larger tonga kermadec trench related earthquake or the kuwae caldera collapse in 1452 1453 ad we recognise that as further research is carried out in the pacific we will greatly improve our abilities to identify past sources and the magnitude and frequency of past events from these areas this can only serve to improve our understanding of the regional risk from tsunamis

northwest pacific typhoons documented by the philippine jesuits 1566 1900 in recent years the population and the value of properties in areas prone to tropical cyclone tc have increased dramatically this has caused more attention to be placed on the characterization of tc climatologies and the identification of the role that factors such as the main teleconnection patterns may play in tc variability due to the timescales involved the instrumental records have proven too short to provide a complete picture thus documentary and other paleoclimatological techniques have been used to reconstruct tc occurrence this has been done mostly for the atlantic basin whereas in the pacific basin fewer attempts have been made the aim of this paper is to provide a high resolution chronology of typhoons and intense storms occurring in the philippine islands and their vicinity for the period 1566 1900 the chronology is based upon the writings of the spanish jesuit miguel selga who produced the original work at the beginning of the 20th century the sources reliability and completeness of the chronology are examined critically a total of 652 events are included 524 of which are reported as typhoons the rest being considered as tropical storms for each of these classes the landfall location and the track when sufficient information is available have been drawn this chronology is an indispensable step toward a final and complete typhoon record in the western pacific basin

foraminifera reveal a shallow nearshore origin for overwash sediments deposited by tropical cyclone pam in vanuatu south pacific abstract tropical cyclone inundation is a major threat to the highly exposed islands of the south pacific this vulnerability was highlighted in march 2015 when tropical cyclone tc pam made landfall on vanuatu as a category 5 storm impacting coastlines with storm surges that produced high water marks up to 7 m above mean sea level msl and deposited overwash sediments up to 400 m inland we examined the foraminiferal assemblages contained within tc pam sediments at two locations in vanuatu a mixed carbonate embayment at manuro on efate island and a volcaniclastic beach at port resolution bay on tanna island at manuro the tc pam sediments were up to 10 cm thick and composed of coarse to medium sand that contained abundant foraminifera 955 to 2015 individuals per 5 cm3 and fragments of corals and mollusks at port resolution bay tc pam sediments were up to 44 cm thick and composed of medium sand sized volcaniclastics with low to moderate abundances of foraminifera 27 to 206 individuals per 5 cm3 tc pam sediments could be discriminated from underlying units by a sharp basal contact an abrupt decrease in organic matter and an increase in the concentration of foraminifera foraminiferal assemblages between the two sites varied in terms of taxonomy and taphonomy at both sites the tc pam assemblage was generally dominated by intertidal e g amphistegina spp baculogypsina sphaerulata calcarina mayori elphidium spp pararotalia spp and subtidal e g peneroplis pertusus quinqueloculina spp foraminifera that are characteristic of beach reef flat and reef crest environments the tc pam assemblage at manuro was characterized by individuals that were dominantly unaltered i e pristine but also those that showed signs of abrasion including edge rounded fragments by contrast tc pam sediments at port resolution bay contained fewer unaltered and more corraded i e combined influence of corrosion and abrasion foraminifera we compared modern surface foraminiferal distributions with those from tc pam sediments to assess provenance partitioning around a medoid pam cluster analysis discriminated six subenvironments within the modern coastal zone open bay forereef reef crest reef flat mangrove and beach discrete intervals sampled from tc pam sediments at manuro were individually clustered with the surface samples and revealed a shallow nearshore to supratidal reef crest to beach 4 9 to 1 3 m above msl source for the sand

quantitative vertical zonation of salt marsh foraminifera for reconstructing former sea level an example from new jersey usa we present a quantitative technique to reconstruct sea level from assemblages of salt marsh foraminifera using partitioning around medoids pam and linear discriminant functions ldf the modern distribution of foraminifera was described from 62 surface samples at three salt marshes in southern new jersey pam objectively estimated the number and composition of assemblages present at each site and showed that foraminifera adhered to the concept of elevation dependent ecological zones making them appropriate sea level indicators application of pam to a combined dataset identified five distinctive biozones occupying defined elevation ranges which were similar to those identified elsewhere on the u s mid atlantic coast biozone a had high abundances of jadammina macrescens and trochammina inflata biozone b was dominated by miliammina fusca biozone c was associated with arenoparrella mexicana biozone d was dominated by tiphotrocha comprimata and biozone e was dominated by haplophragmoides manilaensis foraminiferal assemblages from transitional and high salt marsh environments occupied the narrowest elevational range and are the most precise sea level indicators recognition of biozones in sequences of salt marsh sediment using ldfs provides a probabilistic means to reconstruct sea level we collected a core to investigate the practical application of this approach ldfs indicated the faunal origin of 38 core samples and in cross validation tests were accurate in 54 of 56 cases we compared reconstructions from ldfs and a transfer function the transfer function provides smaller error terms and can reconstruct smaller rsl changes but ldfs are well suited to rsl reconstructions focused on larger changes and using varied assemblages agreement between these techniques suggests that the approach we describe can be used as an independent means to reconstruct sea level or importantly to check the ecological plausibility of results from other techniques

the sedimentary record of the 2005 hurricane season from the mississippi and alabama coastlines abstract the instrumental record of hurricane activity is too short to fully capture the occurrence of the rare but most destructive hurricanes therefore obtaining a record of present and past landfalling hurricanes and their extent of geological and ecological impacts is one means to assess future risk reveal the spatial and temporal variability of hurricane activity and decipher its relationship with global climatic changes we rapidly dispatched survey teams to collect the readily available but perishable data of hurricanes katrina and rita storm surge from two salt marshes in mississippi and one salt marsh in alabama in mississippi we recorded hurricane katrina storm surge heights greater than 7 5 m north american vertical datum 88 navd88 with inland extents in excess of 700 m whereas in alabama the maximum recorded storm surge was 3 43 m navd88 at one salt marsh in mississippi we recorded the maximum inland extent and elevation of maximum penetration of hurricane rita as 370 m and 3 43 m navd88 respectively we observed a three dimensional distribution of hurricane induced storm surge deposits that tapered landward overlying salt marsh sediment there was a sharp or erosional boundary between the pre storm surge and storm surge sedimentary units which was accompanied by a change in color and lithology the overlying storm surge sediment unit was coarser than the pre storm surge unit with a lower organic content the thickness of the hurricanes katrina and rita storm surge sediments ranged from 9 to 13 cm and approximately 7 cm respectively foraminiferal analyses revealed a virtual absence of tests within the storm surge sediments whereas abundant agglutinated foraminifera were found in the underlying salt marsh deposits

distinguishing tsunami and storm deposits an example from martinhal sw portugal abstract geological identification of past tsunamis is important for risk assessment studies especially in areas where the historical record is limited or absent the main problem when using the geological evidence is to distinguish between tsunami and storm deposits both are high energy events that may leave marine traces in coastal stratigraphic sequences at martinhal sw portugal both storm surge and tsunami deposits are present at the same site within a single stratigraphic sequence which makes it suitable to study the differences between them excluding variations caused by local factors the tsunami associated with the lisbon earthquake of november 1st 1755 ad had a major impact on the geomorphology and sedimentology of martinhal it breached the barrier and laid down an extensive sheet of sand as described in eyewitness reports besides the tsunami deposit the stratigraphy of martinhal also displays evidence for storm surges that have breached and overtopped the barrier flooding the lowland and leaving sand layers both marine derived flood deposits show similar grain size characteristics and distinctive marine foraminifera the most important differences are the rip up clasts and boulders exclusively found in the tsunami deposit and the landward extent of the tsunami deposit that everywhere exceeds that of the storm deposits identification of both depositional units was only possible using a collection of different data and extensive stratigraphical information from cores as well as trenches

foraminifera as an indicator of overwash deposits barrier island sediment supply and barrier island evolution folly island south carolina abstract micropaleontological analysis of four vibracores from back barrier marshes of folly island south carolina detected intervals of storm deposited sediment individual washover intervals were not detectable from lithology alone but only in conjunction with associated foraminifera washovers contained more modern offshore and oligo miocene genera and total calcareous foraminifera than background marsh samples the presence of tertiary foraminifera in the back barrier cores from folly island supports the hypothesis that much of the sediment for barrier island migration is derived from offshore foraminiferal analyses of back barrier cores were also used to calculate relative bioturbation rates by the method of officer and lynch officer c b lynch d r 1983 mixing sedimentation rates and age dating for sediment cores mar geol 46 261 278 eqs 10 14 in all cores the current depositional environment correlated well with the expected mixing parameter g the highest mixing parameter greatest signal attenuation was recorded in a core from a low marsh creek side environment whereas the lowest mixing parameter least smearing of signal was recorded in a high marsh core

surf beat induced overwash during typhoon haiyan deposited two distinct sediment assemblages on the carbonate coast of hernani samar central philippines abstract wave set up steepened and accentuated the storm surge during typhoon haiyan in november 2013 resulting in bore like flooding with surge heights of 7 m and flow velocities reaching 5 m s 1 on the open sea coastal plain near hernani this study investigates two distinct sediment assemblages left behind by the coastal flooding associated with this surge the first assemblage consists of numerous coastal boulders that now occupy the reef flat and the second pertains to a laterally extensive sand sheet that blanketed the coastal plain up to 300 m inland the majority of the boulders has b axes between 1 and 2 m weigh no 10 t and were originally submerged on the reef edge the boulders found more landwards of the reef edge were potentially lying loosely on the reef flat prior to haiyan in contrast the coarse carbonate sand sheet starts at 10 m inland of the current shoreline and has a maximum thickness of 10 cm and gradually thins to 3 mm at 300 m inland the haiyan sand contains moderate concentrations of foraminifera amphistegina spp baculogypsina sphaerulata and peneroplis spp that were both abraded and unaltered pointing to a reef flat and beach source for the sand sediment transport inverse modeling complements previous flow velocity estimates using numerical modeling which altogether indicate sustained high velocity overland flow despite the presence of coral reefs and mangroves as natural defenses to extreme waves

carbonate sediment transport pathways based on foraminifera case study from frank sound grand cayman british west indies foraminifera can be used to determine the source s of carbonate sediment and the directions of sediment transport in shallow coastal lagoons such as frank sound on the south central coast of grand cayman these determinations based on the distribution of foraminiferal assemblages and tracer species numerically abundant species that live in known physiographic units and or ecological conditions show that the lagoonal sediments are a mixture of grains that originated in the lagoon and forereef the variable proportions of these foraminifera throughout the lagoon reflects the dynamic processes that control lagoonal sedimentation amphistegina gibbosa discorbis rosea and asterigerina carinata lived in the forereef environment the fact that these tracer species are found throughout frank sound and in the beach sands shows that they were transported across the reef crest and the lagoon abrasion resistant archaias angulatus a tracer species indicative of a lagoonal setting forms up to 50 of foraminiferal assemblages found in the lagoonal sediments preferential winnowing of small tests from these populations indicates sorting under high energy conditions the vertical distribution of the forereef and lagoonal foraminifera in the sediment blanket that covers the floor of frank sound indicates that these processes are temporally persistent transportation of forereef foraminifera into and around the lagoon and sorting of the lagoonal foraminifera cannot take place under normal conditions when the tranquil lagoon is characterized by weak currents storms and or hurricanes however generate short lived high energy events that can move and sort the sediment and foraminifera at the height of a storm water and sediment are moved over the reef and then piled and held onshore by the onshore winds and the constant flow of water over the reef and across the lagoon these currents can mix some of the lagoonal and forereef sediments as a storm wanes however the piled water flows offshore via strong rip currents that pass into the ocean through the channels which transect the reef these currents winnow and or strip sediment from the lagoon and may transport lagoonal sediments into the forereef area as a result residual lagoonal sediment is commonly characterized by larger and abrasion resistant foraminifera

asian summer monsoon simulated by a global cloud system resolving model diurnal to intra seasonal variability 1 interaction of convection and circulation is key to the asian summer monsoon but difficult to represent in global models here we report results from simulations for the summer of 2004 by a global cloud system resolving model nicam at both 14 and 7 km horizontal resolution nicam simulates the observed monsoon circulation patterns and the northward propagation of precipitation the 7 km run simulates summer mean precipitation maxima in narrow bands along the western ghats himalayan foothills the arakan yoma highlands and the annamite range precipitation 1 is modulated by orography 2 is affected by synoptic scale systems and 3 displays a pronounced diurnal cycle especially over indo china with its strong weak signal propagating westward eastward in the wet dry phase of the intraseasonal oscillation this set of simulations captures these intraseasonal changes of the indian monsoon with high fidelity from june to early july nicam exhibits a positive bias in precipitation over the indian ocean common to atmospheric models with prescribed sea surface temperature this calls for the inclusion of ocean atmosphere coupling process to improve monsoon simulation skills

high energy marine flood deposits on astypalaea island greece possible evidence for the ad 1956 southern aegean tsunami high energy marine sediments are described from livadia and stavros astypalaea island greece which are tentatively interpreted to be associated with the southern aegean tsunami of 9th july ad 1956 at livadia the marine provenance of imbricated pebble deposits referred to here as the imbricated clast unit or icu are inferred from two observations firstly the similarity between the clasts comprising the icu and contemporary beach sediments and secondly the inclusion of foraminiferal tests within the sediment matrix derivation from the ad 1956 tsunami rather than from a storm surge is inferred from the uniqueness of the deposits within the sedimentary record their distinct imbrication and 137cs and 210pb dating of overlying and underlying sediments the top of the icu occurs at 2 00 metres above sea level m a s l indicating a minimum flood level at this location at stavros a gravel with rounded clasts incorporating marine mollusca is found on exposed cliff surfaces up to an elevation of 10 00 m a s l these gravels are also interpreted as having been deposited by the ad 1956 tsunami the elevation of the deposits and topographic observations indicate that previously reported run up elevations were over estimated the results shown here represent the first systematic investigation into sedimentary deposits possibly associated with a modern tsunami within the aegean sea region of greece

ichnofauna record cryptic marine incursions onto a coastal floodplain at a key lower mississippian tetrapod site ichnofossils from a lower mississippian tournaisian coastal plain succession with a rich vertebrate fauna including early tetrapods record repeated short lived marine interactions that influenced floodplain lake development and ecosystems the ichnofauna contrasts with the more typical scoyenia ichnofacies of other devonian carboniferous tetrapod sites in the tournaisian ballagan formation of the scottish borders chondrites is identified in 128 horizons within a 500 m succession and is associated with lesser occurrences of phycosiphoniform burrows diplocraterion rhizocorallium and zoophycos chondrites and phycosiphoniform burrows commonly occur within dolostones interpreted as part of a saline hypersaline lake facies association containing a non marine to marginal marine macrofauna of bivalves ostracods spirorbis serpula and sarcopterygian fish marine scolecodonts are reported from 18 horizons of diverse lithology four of which co occur with chondrites the single colonisation single tier high ichnofabric index and thin beds mean 10 cm thick that characterise chondrites horizons indicate 1 adverse environmental conditions 2 rapid colonisation of the sediment and 3 short lived bioturbation episodes other ichnotaxa identified are monocraterion and asterosoma which occur exclusively within the overbank or fluvial facies associations and are here interpreted to have lived in freshwater conditions the chondrites trace makers are interpreted as having originated in shallow marine waters and were transported into floodplain lakes by storm surge events although a few examples suggest more significant transgressions ichnofossils are much more common than marine body fossils or scolecodonts and thus record cryptic marine incursions that might otherwise remain unidentified this study contributes to our understanding of the complex mosaic of environments present when terrestrial tetrapods first appeared

sedimentary evidence of intense hurricane strikes from new jersey nine vibracores from the backbarrier marsh at whale beach new jersey reveal three large scale overwash deposits associated with historic and prehistoric storms the uppermost and smallest overwash fan was deposited in the ash wednesday northeaster of march 5 8 1962 a second more substantial overwash fan between 100 and 35 cm depth dates to the late eighteenth or early nineteenth century this fan was most likely deposited during the 1821 hurricane the only intense hurricane to make landfall in new jersey in the past 350 yr a third larger overwash fan between 200 and 300 cm depth was deposited between a d 1278 and 1438 and is likely the result of a prehistoric intense hurricane strike the combination of historical and stratigraphic evidence indicates that two intense hurricanes winds 50 ms 21 have likely made landfall on the southern new jersey coast in the past 700 yr resulting in an annual landfall probability of 0 3

reconstruction of prehistoric landfall frequencies of catastrophic hurricanes in northwestern florida from lake sediment records abstract sediment cores from western lake provide a 7000 yr record of coastal environmental changes and catastrophic hurricane landfalls along the gulf coast of the florida panhandle using hurricane opal as a modern analog we infer that overwash sand layers occurring near the center of the lake were caused by catastrophic hurricanes of category 4 or 5 intensity few catastrophic hurricanes struck the western lake area during two quiescent periods 3400 5000 and 0 1000 14 c yr b p the landfall probabilities increased dramatically to ca 0 5 per yr during an hyperactive period from 1000 3400 14 c yr b p especially in the first millennium a d the millennial scale variability in catastrophic hurricane landfalls along the gulf coast is probably controlled by shifts in the position of the jet stream and the bermuda high

sediment grains moved by passing tsunami waves tsunami deposits in deep water abstract tsunamis propagating in the open ocean have associated horizontal particle velocities that do not change with depth yet the limiting water depth where a tsunami of given characteristics will initiate sediment motion remains unknown based upon linear wave theory and a parametrization of the shields curve equations are derived and solved using an iterative scheme to address the topic of grain movement by tsunami waves as a function of water depth and wave amplitude the focus is on waves in deep water where tsunami waves behave linearly and on non cohesive sediment grains furthermore the question is addressed of which grain sizes are picked up on a sloping beach as the wave shoals according to the results even the boxing day tsunami in 2004 was incapable of moving fine sand in water deeper than 985 m in the bay of bengal and 335 m in the indian and pacific oceans the results suggest that tectonic tsunamis of size equal to or smaller than the boxing day tsunami cannot initiate motion of deep water cohesionless sediments that can be correlated on an oceanic basin wide scale

sedimentological characteristics of the 2015 tropical cyclone pam overwash sediments from vanuatu south pacific abstract the interpretation of sediments deposited by prehistoric tropical cyclones tc s is limited by a lack of modern analogues particularly in the south pacific on 13 march 2015 tc pam made landfall on vanuatu reaching category 5 intensity with 10 minute sustained wind speeds as high as 270 km h three months after landfall we measured flow height terrain elevation plus storm flow depth and inland extent of tc pam s maximum coastal inundation composed of astronomical tides storm surge and superimposed storm waves and described the sedimentological characteristics of the tc pam overwash sediments from trenches and transects at two sites manuro and port resolution bay at manuro a mixed carbonate embayment the maximum flow height was 5 29 m mean sea level msl with an inland extent of 106 m the tc pam sediments transition from a coarse to medium grained mean 1 07 carbonate sand 10 cm thick to pumice 18 cm thick that extends 400 m inland into lake otas the tc pam overwash sediments are characterized by a coarsening upward sequence 1 45 to 0 23 followed by a finer grained eolian cap at port resolution bay a volcaniclastic beach prb the maximum flow height was 3 30 m msl 1 51 m flow depth with an inland extent of 117 m the tc pam overwash sediments transition from a medium grained mean 1 76 volcanic sand 44 cm thick to pumice 5 cm thick that extends 320 m from the shoreline a subtle fining upward sequence was present in trench prb2 whereas prb1 prb3 and prb4 contained tc pam sediments that were laminated and showed little to no vertical gradation in grain size at prb we applied an inverse sediment transport model to reconstruct maximum flow depths using laboratory derived settling velocities and the distance from the berm the reconstructed flow depths at prb2 1 43 m prb3 1 36 m and prb4 1 34 m compare favorably with the observed estimate 1 51 m illustrating the applicability of the inverse sediment transport model to reconstruct flow depths of prehistoric landfalling tc s

an ocean coupling potential intensity index for tropical cyclones american geophysical union 2013 this article is posted here by permission of american geophysical union for personal use not for redistribution the definitive version was published in geophysical research letters 40 2013 1878 1882 doi 10 1002 grl 50091

a decadally resolved paleohurricane record archived in the late holocene sediments of a florida sinkhole article i nfo a 4500 year record of hurricane induced storm surges is developed from sediment cores collected from a coastal sinkhole near apalachee bay florida recent deposition of sand layers in the upper sediments of the pond was found to be contemporaneous with significant historic storm surges at the site modeled using slosh and the best track post 1851 a d dataset using the historic portion of the record for calibration paleohurricane deposits were identified by sand content and dated using radiocarbon based age models marine indicative foraminifera some originating at least 5 km offshore were present in several modern and ancient storm deposits the presence and long term preservation of offshore foraminifera suggest that this site and others like it may yield promising microfossil based paleohurricane reconstructions in the future due to the sub decadal 7 years resolution of the record and the site s high susceptibility to hurricane generated storm surges the average local frequency of recorded events approximately 3 9 storms per century is greater than that of previously published paleohurricane records from the region the high incidence of recorded events permitted a time series of local hurricane frequency during the last five millennia to be constructed variability in the frequency of the largest storm layers was found to be greater than what would likely occur by chance alone with intervals of both anomalously high and low storm frequency identified however the rate at which smaller layers were deposited was relatively constant over the last five millennia this may suggest that significant variability in hurricane frequency has occurred only in the highest magnitude events the frequency of high magnitude events peaked near 6 storms per century between 2800 and 2300 years ago high magnitude events were relatively rare with about 0 3 storms per century occurring between 1900 and 1600 years ago and between 400 and 150 years ago a marked decline in the number of large storm deposits which began around 600 years ago has persisted through present with below average frequency over the last 150 years when compared to the preceding five millennia

source of high tsunamis along the southernmost ryukyu trench inferred from tsunami stratigraphy abstract four paleotsunamis deposits are exposed in a trench on the coastal lowland north of the southern ryukyu subduction zone trench radiocarbon ages on coral and bivalve shells show that the four deposits record tsunamis date from the last 2000 yrs including a historical tsunami with a maximum run up of 30 m in 1771 for an average recurrence interval of approximately 600 yrs ground fissures in a soil beneath the 1771 tsunami deposit may have been generated by stronger shaking than recorded by historical documents the repeated occurrence of the paleotsunami deposits supports a tectonic source model on the plate boundary rather than a nontectonic source model such as submarine landslides assuming a thrust model at the subduction zone the seismic coupling ratio may be as low as 20

microfossils from coastal environments as indicators of paleo earthquakes tsunamis and storms abstract coastal risk assessment and hazard mitigation require datasets on centennial and millennial temporal scales to capture natural variability and multiple occurrences of the largest but least frequent events coastal sediments from low energy depositional environments archive geologic evidence of paleo earthquakes tsunamis and storms many of the best reconstructions of these events are derived from changes in microfossil diatoms foraminifera and pollen assemblages in this review we explain how microfossils are used to reconstruct records of paleoearthquakes by quantifying the amount of coseismic and interseismic vertical land movements along tectonically active coastlines examples from the united states alaska and the pacific northwest japan and chile show that microfossil based transfer functions may provide continuous records of vertical land movement during earthquake deformation cycles we discuss how microfossil habitat preferences and taphonomic character are used to constrain sediment provenance e g beach nearshore or offshore sources and identify overwash deposits and how this information can be used to reconstruct the recurrence of tsunamis and storms analysis of overwash deposits from thailand and malaysia indicates the ability of microfossils to resolve individual waves within tsunami sediments and an example from the sendai coastal plain in japan uses foraminifera to ascribe a beach to nearshore provenance for the 2011 tohoku tsunami deposit finally we present recent examples from the gulf of mexico on the use of foraminifera to estimate the volume and distance of transport of storm overwash from hurricanes

records of prehistoric hurricanes on the south carolina coast based on micropaleontological and sedimentological evidence with comparison to other atlantic coast records singleton swash on the south carolina coast provides an extended record of storm events for this coast we used experience gained by looking at storm traces detected as layers of offshore foraminifera intercalated with marsh sediments from a known storm in the area hugo which occurred in 1989 to detect storm horizons from the sediments that have been accumulating in singleton swash since 5700 yr b p we suggest here that the most intense storm activity occurred in the 0 1000 yr b p interval six storms only three occurred in the 1000 2000 yr b p interval and two in the 2000 3000 yr b p time interval calibrated radiocarbon years there was one giant storm in the pre 5000 yr b p interval a sea level oscillation in the 3500 5000 yr b p interval appears to have destroyed most records during that period previous work suggests that the position of the bermuda or azores high influences the direction of general storm paths for major north atlantic hurricanes a position of the bermuda high farther to the south tends to force storms into the gulf of mexico whereas a northern position allows them to track up the atlantic coast results here combined with results of other workers on the gulf coast suggest a more southern position for the bermuda high causing more storms on the gulf coast in the interval of 1000 3400 yr b p conversely a more northern position during the past 1000 yr is suggested to have contributed to higher frequencies of storms on the atlantic coast in that period to test this hypothesis modern records of the movement of the north atlantic oscillation nao which controls the position of the bermuda high have been compared with historical records of hurricane tracks over the twentieth century there does appear to be a strong correlation between the position of the nao and the track the storms have pursued in modern times

holocene coastal evolution and evidence for paleotsunami from a tectonically stable region tasmania australia stratigraphic investigations of three coastal waterbodies in southeastern tasmania reveal major paleoenvironmental phases related to sea level change and anomalous deposits consistent with tsunami