Tsunamigenic deposit

We evaluated sediment sources of the 2011 Tohoku-Oki tsunami deposits along a 4500 m inland transect from the central east Japan coast, using grain size, mineralogy and foraminifera analysis. The tsunami run-up height in our study area was 13 to 20 m near the coastline, 1.4 to 2.8 m in the middle of the valley and 1.3 m around the inundation limit. The inundation distance was around 4800 m. The deposits are composed of sand and mud and show a fining and thinning trend. Mineral composition of the tsunami deposits was similar to that of coastal dune and beach deposits, indicating that most of the tsunami sediment originated from there. A minor foraminifera population in the deposit (≤ 15 specimens per 5 grams of sample compared with ≥ 100 specimens per 1 gram for typical marine sediment) indicates that marine sediments source was not dominant. Topography played an important role in sediment transport process and deposit distribution. The run-up wave accelerated faster in concave topography, became more erosive, and resulted in a thin deposit in topographic lows. We infer that the deposits up to 2300 m from the coastline were deposited by bedload and suspension, whereas suspension was responsible for deposits farther inland.

We report initial results from our recent field survey documenting the inundation and resultant deposits of the 2011 Tohoku-oki tsunami from Sendai Plain, Japan. The tsunami inundated up to 4.5 km inland but the> 0.5 cm-thick sand deposit extended only 2.8 km ( ...

Fields of dislocated boulders and blocks record catastrophic coastal flooding during strong storms or tsunamis and play a pivotal role in coastal hazard assessment. Along the rocky carbonate coast of Eastern Samar (Philippines) we documented longshore transport of a block of 180 t and boulders (up to 23.5 t) shifted uphill to elevations of up to 10 m above mean lower low water level during Supertyphoon Haiyan on 8 November 2013. Initiation-of-motion approaches indicate that boulder dislocation occurred with flow velocities of 6.3–8.3 m s<sup>−1</sup> which significantly exceeds depth-averaged flow velocities of a local coupled hydrodynamic and wave model (Delft3D) of the typhoon with a maximum…

The site of Lechaion on the Gulf of Corinth, in use at least from the sixth century B.C.E. to the sixth century C.E., was one of the most important ports in Greece. Little is known, however, about the final abandonment of the harbor and its town in the sixth or seventh century C.E. Although previous historical and archaeological scholarship has associated this abandonment with a supposed tsunami that allegedly destroyed the nearby basilica, there is still debate over the dating of the abandonment and the strength of any tsunamis that may have occurred at the time. The Lechaion Harbor and Settlement Land Project (LHSLP) recently uncovered 2m thick deposits of marine sand and gravel that lie above and below Roman-era remains. Micromorphology was applied to better understand the environmental and anthropogenic processes that shaped the content of the fills, and whether they are the direct result of natural events or were redeposited through dredging during maintenance and reconstruction. More commonly used to understand site-formation processes on prehistoric and Bronze Age sites in the Aegean, archaeological soil micromorphology is the analysis of the in situ relationships between the sediments and their subsequent alteration by environmental conditions. I applied micromorphology to compare sediments from fills and floors across the site to determine the availability of various marine-derived sediments over time and to understand how often the occupants of the site may have used marine sediments to rebuild or maintain the site. Twenty-five micromorphological blocks and one bulk sample were taken from two buildings, one adjacent to the entry channel of the inner harbor and one on the banks of the inner harbor, or " lagoon. " The mineralogical composition, microscopic structures such as bedding, and the shape of pebbles and ceramics were observed via thin-section and recorded in order to compare the transport processes that produced each deposit. In particular, a marine-derived sand containing basalt fragments appears both in a large, apparently natural deposit, and in a prepared floor, suggesting perhaps that an unusual natural marine deposit, perhaps from a tsunami, was later utilized for its unique appearance. While further analysis is required, micromorphological analysis at Lechaion promises a fuller understanding of the use and abandonment of the site as well as the resilience of populations on the seismically active Corinthian coast.

Although the Gulf of Aqaba-Eilat is located in the tectonically active northern Red Sea, it has been described as low-risk with regard to tsunami activity because there are no modern records of damaging tsunami events and only one tsunami (1068 AD) referred to in historical records. However, this assessment may be poorly informed given that the area was formed by and is located along the seismically active Dead Sea Fault, its population is known to fluctuate in size and literacy in part due to its harsh hyper-arid climate, and there is a dearth of field studies addressing the presence or absence of tsunamigenic deposits. Here we show evidence from two offshore cores for a major paleotsunami that occurred ~2300 years ago with a sedimentological footprint that far exceeds the scarce markers of the historically mentioned 1068 AD event. The interpretation is based on the presence of a laterally continuous and synchronous, anomalous sedimentological deposit that includes allochtonous inclusions and unique structural characteristics. Based on sedimentological parameters, these deposits could not be accounted for by other transport events, or other known background sedimentological processes.

In the Manavgat Sub-basin (southwestern Turkey) being a part of the Eastern Mediterranean marginal basins, an erosional surface (LPES) which was formed during the sea-level fall of the Late Pliocene regression is firstly exposed in the study. This hiatus is overlied by the Lower Pleistocene paleotsunami deposits which indicate a rapid sea flooding and returning to marine environment after probable earthquakes at the bottom of Mediterranean, reconstracting epicontinental shelf or coastal flat. New sedimentological and biostratigraphical data obtained from the examined rock samples of thirteen spots indicate to be formed a new regressive succession on the LPES after occurring a subsidence of sea-bottom and developing a forced-transgression on the coastal plane of the Manavgat Sub-basin.

Keywords: Tsunami deposits, early Pleistocene, Late Pliocene Erosional Surface, calcareous nannofossils.

The draft paper as at 24th April which is updated from the draft made for the oral presentation session (5th April 2017 does not contain any references and text errors needed corrections). The paper is still being worked on with more sections being added with some aspect areas clarified in more detail. Others are being reviewed. Due to the closure of the Parliament in the UK early for the snap elections, the text is still unfinished and will be resumed for the new Parliament session with no end date set yet. The document is best viewed by a download to Microsoft Word as web browsers tend to muddle the layout. Please note that the ice sheet mass balance changes occur mainly in nearby Iceland, Jan Mayen and the Mid-Atlantic Ridge rather than Greenland itself. (High viscous, low nucleation events pushing very cool, effusive, almost 'solid' lava incursions vertically up like the Mascarene volcanism of Mauritius are rare anomalies from a misaligned hotspot influencing further afield - and therefore far less likely.)

My draft notes for the Environmental Audit Committee's oral discussions on 5th April 2017 at the Houses of Parliament without references given here. The oral session draft was published on 28th April 2017 with the final text still in reviews to include important additional items omitted on the draft text. The full text will have soon all the necessary references. Due to this text being a draft the text and images appear unaligned with the text due to it being draft for the session on 5th April. However, the Parliament decided nevertheless to publish this semi-complete version. More up-to-date text (.docx format) is on Drafts section. It has been receiving reviews and I will publish the final text separately once all the external input has been duly received and processed.