scholarly journals Run-up, inundation, and sediment characteristics of the 22 December 2018 Sunda Strait tsunami, Indonesia

2020 ◽  
Vol 20 (4) ◽  
pp. 933-946 ◽  
Author(s):  
Wahyu Widiyanto ◽  
Shih-Chun Hsiao ◽  
Wei-Bo Chen ◽  
Purwanto B. Santoso ◽  
Rudy T. Imananta ◽  
...  
Keyword(s):  
Average Distance ◽  
Fine Sand ◽  
Coarse Sand ◽  
Sediment Characteristics ◽  
Sediment Samples ◽  
The North ◽  
Sediment Deposits ◽  
Run Up ◽  
Tsunami Run Up ◽  
Krakatau Volcano

Abstract. A tsunami caused by a flank collapse of the southwest part of the Anak Krakatau volcano occurred on 22 December 2018. The tsunami affected the coastal areas located at the edge of the Sunda Strait, Indonesia. To gain an understanding of the tsunami event, field surveys were conducted a month after the incident. The surveys included measurements of run-up height, inundation distance, tsunami direction, and sediment characteristics at 20 selected sites. The survey results revealed that the run-up height reached 9.2 m in Tanjungjaya and an inundation distance of 286.8 m was found at Cagar Alam, part of Ujung Kulon National Park. The tsunami propagated radially from Anak Krakatau and reached the coastal zone with a direction between 25 and 350∘ from the north. Sediment samples were collected at 27 points in tsunami deposits with a sediment thickness of 1.5–12.7 cm. The average distance from the coast of the area with significant sediment deposits and the deposit limit are 45 % and 73 % of the inundation distance, respectively. Sand sheets were sporadic, highly variable, and highly influenced by topography. Grain sizes in the deposit area were finer than those at their sources. The sizes ranged from fine sand to boulders, with medium sand and coarse sand being dominant. All sediment samples had a well-sorted distribution. An assessment of the boulder movements indicates that the tsunami run-up had minimum velocities of 4.0–4.5 m s−1.

scholarly journals Runup, Inundation, and Sediment Characteristics of 22 December 2018 Indonesia Sunda Strait Tsunami

2019 ◽  
Author(s):  
Wahyu Widiyanto ◽  
Wei-Cheng Lian ◽  
Shih-Chun Hsiao ◽  
Purwanto B. Santoso ◽  
Rudy T. Imananta
Keyword(s):  
Fine Sand ◽  
Coarse Sand ◽  
Sediment Characteristics ◽  
Field Surveys ◽  
Sediment Samples ◽  
Survey Results ◽  
Krakatau Volcano ◽  
Runup Height ◽  
Sand Sheets ◽  
Southwest Part

Abstract. A tsunami caused by a flank collapse of the southwest part of the Anak Krakatau volcano occurred on 22 December 2018. The affected area of the tsunami included a coastal area located at the edge of Sunda Strait, Indonesia. To gain an understanding of the tsunami event, field surveys were conducted a month after the incident. The surveys included measurements of runup height, inundation distance, tsunami direction, and sediment characteristics at 20 selected sites. The survey results revealed that the runup height and inundation distance reached 7.8 m and 292.2 m, both was found at Site Cagar Alam, part of Ujung Kulon National Park. Tsunami propagated radially from its source and arrived in coastal zone with direction was between 25° and 350° from North. Sediment samples were collected at 27 points in tsunami deposits with a sediment thickness of 1.5–12 cm. The distance of the sediment deposit area from the coast was 40 %–90 % of the distance of the inundation caused by the tsunami. The highest elevation of deposits was 60 %–90 % of the highest runup. Sand sheets were sporadic, highly variable, and highly influenced by topography. Grain sizes in the deposit area were finer than those at their sources. The sizes ranged from fine sand to boulders, with medium sand and coarse sand being dominant. All sediment samples had a well sorted distribution. An assessment of the boulder movements indicates that the tsunami runup had minimum velocities of 4.0–4.5 m/s.

The late Wisconsinan olistostrome of the lower Coppermine River valley, Northwest Territories

1986 ◽  
Vol 23 (11) ◽  
pp. 1700-1708 ◽  
Author(s):  
Denis A. St-Onge ◽  
Jean Lajoie
Keyword(s):  
Debris Flows ◽  
Late Quaternary ◽  
Fine Sand ◽  
Coarse Sand ◽  
Coarse Fraction ◽  
River Valley ◽  
Glacial Lake ◽  
The North ◽  
Geologic Record ◽  
Coppermine River

The late Quaternary olistostrome exposed in the lower Coppermine River valley fills a paleovalley that ranges in apparent width from 150 to 400 m and was cut into Precambrian bedrock before the last glaciation. The olistostrome is here named the Sleigh Creek Formation. The coarse fraction of the formation is matrix supported; beds are massive or reversely graded and have sharp, nonerosive contacts. These characteristics suggest deposition of the coarse fraction by debris flows. The olistostrome sequence is bracketed by, and wedged into, a marine rhythmite sequence, which indicates that deposition occurred in a marine environment.About 10 500 years BP glacier ice in the Coronation Gulf lowland dammed the valley to the south, which was occupied by glacial Lake Coppermine. Sediments accumulated in this lake in a 30 m thick, coarsening upward sequence ranging from glaciolacustrine rhythmites of silt and fine sand at the base to coarse sand alluvium, and deltaic gravels at the top. As the Coronation Gulf lowlands became ice free, the Coppermine River reoccupied its former drainage course to the north. The steep south to north gradient and rapid downcutting by the river through the glacial lake sediments produced unstable slope conditions. The resulting debris flows filled a bedrock valley network below the postglacial sea level, forming the diamicton sequence.The interpretation of the Sleigh Creek Formation raises questions concerning silimar diamicton deposits usually defined as "flowtills." More generally, the results of this study indicate that care must be used when attempting paleogeographic reconstructions of "glaciogenic" deposits in marine sequences in any part of the geologic record.

The Sedimentary Structures and Depositional Mechanics of Certain Ordovician Turbidites, Cloridorme Formation, Gaspé Peninsula, Quebec

1975 ◽  
Vol 12 (11) ◽  
pp. 1934-1952 ◽  
Author(s):  
Keith Skipper ◽  
Gerard V. Middleton
Keyword(s):  
Large Scale ◽  
Fine Sand ◽  
Coarse Sand ◽  
Turbidity Currents ◽  
Upstream Migration ◽  
High Concentration ◽  
Sedimentary Structures ◽  
The North ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

Turbidites, belonging to the β1, member, Cloridorme Formation, are exposed on the north shore of the Gaspé Peninsula, Quebec. Their structural attitude is such that vertical sections through turbidite beds are exposed on the wave-cut platform and their strike is approximately parallel to the paleocurrent direction, as shown by sole marks on the bases of beds.Certain thick turbidite beds, in a distal position, display a sequence of sedimentary structures which differs from the sequence defined by Bouma. Three broad divisions are recognized: a basal division consists of either limestone or quartz granule to pebble conglomerate (0–4 cm thick) or coarse sand graywacke or calcareous wacke (0–15 cm thick). Basal divisions of calcareous wacke frequently display ripple-lamination, parallel lamination, or upstream-inclined laminae. Where the upstream inclined laminae form a single set, they occur below a sinuous profile (wavelength 40–80 cm, and amplitude 2–5 cm).A second division (0–330 cm thick) consists in most places of spindle- or globular-shaped calcareous nodules scattered in an argillaceous host. In some beds, streaking and lobing of light colored, carbonate bearing material is associated with these nodules. Internal hemi-ellipsoid structures, arranged en echelon and convex towards the base of the bed, are displayed from the second division. The upper division consists of fine grained siltstone and shale.The upstream-inclined laminae in the basal division of calcareous wacke beds are interpreted as being the result of the upstream migration of antidunes. The nodules within the second division developed as 'pseudo-nodules'. The hemi-ellipsoid structures resemble damped, large scale (macroturbulent) eddies associated with the flow of dense grain dispersions.Correlation of these beds has been achieved over a distance of 12 km. Basal divisions of granule and pebble conglomerate persist over this distance and show that coarse particles may be transported by turbidity currents over long distances. The sedimentary structures of the basal divisions of several calcareous wacke beds might be interpreted as the result of either an increase in flow regime downcurrent, or of nonpreservation of structures at up-current localities.The beds were probably deposited from turbidity currents composed largely of mud and fine sand, but containing a zone of coarse grains concentrated near the bed. The basal division was deposited from this lower zone and a period of traction formed rippled, flat, or antidune bed forms. Stratification in the basal division was preserved by the rapid deposition on top of sediment that settled en masse from the subsequent high concentration body of the current. The formation of a succession of 'quick' beds led to the sedimentation of the second division. The flows responsible for the sequence of structures observed and the downcurrent persistence of the beds probably approached closely a state of 'autosuspension'.

Nematode communities from the North Sea: environmental controls on species diversity and vertical distribution within the sediment

1999 ◽  
Vol 79 (2) ◽  
pp. 253-264 ◽  
Author(s):  
Maaike Steyaert ◽  
Nelia Garner ◽  
Dirk van Gansbeke ◽  
Magda Vincx
Keyword(s):  
Vertical Distribution ◽  
Fine Particles ◽  
Anthropogenic Impacts ◽  
Fine Sand ◽  
Coarse Sand ◽  
Food Sources ◽  
Fine Sediments ◽  
The North ◽  
Environmental Controls ◽  
Belgian Coast

Nematode assemblages were sampled seasonally at three subtidal stations along the Belgian coast. The stations were characterized by muddy sediments (station 115), fine sand (station 702) and fine to coarse sand (station 790). The forces structuring vertical distribution were investigated by evaluating abundance, species composition, diversity and trophic composition, and relating these to sediment composition, redox state and food sources.The nematode assemblages at the two finer grained stations (115, 702) were dominated by Daptonema tenuispiculum and Sabatieria punctata. For both species, the vertical distribution in the sediment seemed not dependent on the redoxchemistry, as former believed for S. punctata, but primarily influenced by food availability. This feature could also be recognized for Ixonema sordidum and Viscosia langrunensis, the most abundant nematodes at the coarse sandy station (790).In general, nematode diversity was regulated primarily by sediment granulometry. Coarser sediments (station 790) yielded more diverse communities compared to the fine sediments (station 115, 702), however seasonal fluctuations and variations with depth into the sediment were not obvious. At the silty stations, when the sediment column was more oxidized in March, overall diversity was higher and showed a positive relationship to the mud content which varied with depth into the sediment. This positive relation is probably explained by an enhanced deposition of organic matter associated with the accumulation of fine particles near the river-mouths. Furthermore, the higher abundance, the lower diversity and the higher dominance found at the two silty stations of the eastern and the western part of the Belgian coast, pointed to a stressed, organically enriched environment.The results demonstrate that controls on nematode community structure are complex and that information at both species and community level are required to properly evaluate the effects of natural and anthropogenic impacts.

Macrobenthic communities of the north-western Ross Sea shelf: links to depth, sediment characteristics and latitude

2010 ◽  
Vol 22 (6) ◽  
pp. 793-804 ◽  
Author(s):  
V.J. Cummings ◽  
S.F. Thrush ◽  
M. Chiantore ◽  
J.E. Hewitt ◽  
R. Cattaneo-Vietti
Keyword(s):  
Ross Sea ◽  
Fine Sand ◽  
Sediment Characteristics ◽  
Explanatory Variables ◽  
The North ◽  
Biogenic Habitat ◽  
Community Variability ◽  
North Western ◽  
Western Ross Sea ◽  
Ross Sea Shelf

AbstractIn early 2004 the Victoria Land Transect project sampled coastal north-western Ross Sea shelf benthos at Cape Adare, Cape Hallett, Cape Russell and Coulman Island from 100–500 m deep. We describe the benthic macrofaunal assemblages at these locations and, to assess the use of seafloor sediment characteristics and/or depth measures in bioregionalizations, determine the extent to which assemblage compositions are related to measured differences in these factors. Percentages of fine sand and silt, the ratio of sediment chlorophyllato phaeophytin, and depth were identified as important explanatory variables, but in combination they explained only 17.3% of between-location differences in assemblages. Consequently, these variables are clearly not strong determinants of macrofaunal assemblage structure. Latitudeper sewas not a useful measure of community variability and change. A significant correlation between both number of individuals and number of taxa and sediment phaeophytin concentration across locations suggests that the distribution of the benthos reflects their response to seafloor productivity. A number of factors not measured in this study have probably influenced the structure and function of assemblages and habitats. We discuss the implications of the results to marine classifications, and stress the need to incorporate biogenic habitat complexity into protection strategies.

scholarly journals Sediment Characterization and Monsoonal Impact on Beach Morphology at the Three Beaches along the Karachi Coast, Pakistan

2021 ◽  
Vol 12 (1) ◽  
pp. 8185
Author(s):  
Sumera Farooq ◽  
Nazia Arshad
Keyword(s):  
Monsoon Season ◽  
High Tide ◽  
Fine Sand ◽  
Coarse Sand ◽  
Sediment Characteristics ◽  
Sand Fraction ◽  
South West ◽  
South West Monsoon ◽  
Tide Level ◽  
West Monsoon

Sediment characteristics plays important role in the determination and functioning of coastal ecosystems. The present study is an attempt to evaluate the variability in sediment characteristics of the three beaches: Clifton, Sandspit and Buleji, at the Karachi coast. The samples were collected during pre-monsoon and south-west monsoon seasons to evaluate the seasonal differences. The sediments of the three sites showed variations in moisture content, organic matter and grain size. The highest mean moisture (27.17%) and organic contents (3.5 %) were recorded from the sediments of Clifton. The maximum fraction of sediments (> 80 %) consist of fine to very fine sand at all studied sites. The sediments of Clifton were high in very fine sand fraction and low in coarse sand fraction as compared to Sandspit and Buleji. The sediments of all the three studied sites are moderately sorted, negatively coarse-skewed and showed leptokurtic distribution. The studied beaches of Clifton, Sandspit and Buleji shows dissimilarity in sediment characteristics as indicated through Cluster and PCA analysis. The monsoonal influence on sediment characteristics was also observed at all the three studied beaches. The strong wave action during SW monsoon season results in the deposition of the coarser sediments at the high tide level thus increasing the steepness of the beaches.

scholarly journals Assessing local impacts of the 1700 CE Cascadia earthquake and tsunami using tree-ring growth histories: a case study in South Beach, Oregon, USA

2021 ◽  
Vol 21 (6) ◽  
pp. 1971-1982
Author(s):  
Robert P. Dziak ◽  
Bryan A. Black ◽  
Yong Wei ◽  
Susan G. Merle
Keyword(s):  
Ground Truth ◽  
Douglas Fir ◽  
Cascadia Subduction Zone ◽  
The South ◽  
Old Growth ◽  
Tsunami Inundation ◽  
The North ◽  
Resolution Model ◽  
Run Up ◽  
Tsunami Run Up

Abstract. We present an investigation of the disturbance history of an old-growth Douglas-fir (Pseudotsuga menziesii) stand in South Beach, Oregon, for possible growth changes due to tsunami inundation caused by the 1700 CE Cascadia Subduction Zone (CSZ) earthquake. A high-resolution model of the 1700 tsunami run-up heights at South Beach, assuming an “L”-sized earthquake, is also presented to better estimate the inundation levels several kilometers inland at the old-growth site. This tsunami model indicates the South Beach fir stand would have been subjected to local inundation depths from 0 to 10 m. Growth chronologies collected from the Douglas-fir stand shows that trees experienced a significant growth reductions in the year 1700 relative to nearby Douglas-fir stands, consistent with the tsunami inundation estimates. The ±1–3-year timing of the South Beach disturbances are also consistent with disturbances previously observed at a Washington state coastal forest ∼220 km to the north. Moreover, the 1700 South Beach growth reductions were not the largest over the >321-year tree chronology at this location, with other disturbances likely caused by climate drivers (e.g., drought or windstorms). Our study represents a first step in using tree growth history to ground truth tsunami inundation models by providing site-specific physical evidence.

scholarly journals SEDIMENTOLOGICAL PROPERTIES OF THE 2010 MENTAWAI TSUNAMI DEPOSIT

2016 ◽  
Vol 27 (2) ◽  
pp. 55
Author(s):  
Yudhicara Yudhicara ◽  
Andrian Ibrahim
Keyword(s):  
Grain Size ◽  
Fine Sand ◽  
Coarse Sand ◽  
Transport Processes ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Tsunami Deposit ◽  
Tsunami Deposits ◽  
Sponge Spicule ◽  
Run Up

Post tsunami survey of the October 25, 2010, Mentawai tsunami, has been carried out by a collaboration team of Indonesian-German scientists from 20 to 28 November 2010. One activity of the researches were investigation on tsunami deposits along the coast following the event that devastated the islands of Sipora, North Pagai and South Pagai. Sedimentological properties of Mentawai tsunami deposit were explained by this study, from both megascopic and laboratory result. In general, beaches along the study area are underlying by a stretch of reef limestone, sediments mostly composed of white sand while grey sand was found only at Malakopa. Tsunami sediments were taken from 20 locations, start from Betumonga at Sipora Island until Sibaru-baru Island at the southern tip of the study area. The thickness of tsunami deposits are ranged between 1.5 and 22 cm, which are generally composed of fine to coarse sand in irregular boundaries with the underlying soil. Based on grain size analysis, variation of sedimentological properties of tsunami deposits range between phi=-0,5793 and phi=3,3180 or very coarse to very fine sand. Tsunami deposits mostly have multiple layers which described their transport processes, run up at the bottom and back wash at the top. Structural sediments such as graded bedding of fining upward, parallel lamination and soil clast were found. The grain size distribution curves show two types of mode peak, unimodal and multimodal which are indication of different sorting condition representing the source materials. While segment grain size accumulative plot generally shows domination of dilatation and traction transport mechanism rather than suspension. In general, very rare fossils were found from Mentawai tsunami deposit, but those findings gave information on how depth tsunami start to scour the seafloor and transport it landward, such as an abundance of Sponge spicule was found which indicate shallow water environments (20-100 m seafloor depth). Keywords: 2010 Mentawai tsunami, tsunami deposit, grain size analysis, fossils identification. Survei pasca-tsunami Mentawai 25 Oktober 2010, telah dilakukan oleh Tim gabungan Indonesia-Jerman pada tanggal 20 - 28 November 2010. Salah satunya adalah melakukan identifikasi endapan tsunami yang ditemukan di sepanjang pantai yang terlanda tsunami di Pulau Sipora, Pagai Utara dan Pagai Selatan. Berdasarkan hasil penelitian baik megaskopik maupun analisis laboratorium, dalam tulisan ini dapat dijelaskan mengenai sifat-sifat sedimentologi dari endapan tsunami Mentawai. Secara umum litologi penyusun pantai di daerah penelitian disusun oleh hamparan batugamping terumbu, sebagian disusun oleh pasir berwarna putih, sedangkan di Malakopa tersusun oleh endapan pasir pantai berwarna abu-abu. Berdasarkan hasil analisis laboratorium, diperoleh variasi sifat sedimentologi, seperti kisaran ukuran butir endapan tsunami antara -0,5793 phi dan 3,3180 phi, yaitu pasir sangat kasar hingga sangat halus. Endapan tsunami umumnya memiliki beberapa lapis yang menunjukkan adanya proses transportasi, seperti saat air naik (run up) di lapisan bagian bawah dan surut di bagian atas, yang ditunjukkan dengan adanya perbedaan ukuran butir. Struktur sedimen ditemukan seperti adanya perubahan besar butir secara berangsur menghalus ke bagian atas, perlapisan sejajar dan fragmen tanah yang terperangkap dalam sedimen. Kurva distribusi ukuran butir memperlihatkan dua jenis model puncak, yaitu unimodal dan multimodal yang memperlihatkan kondisi pemilahan yang berbeda yang menunjukkan kondisi sumber material endapan tsunami, sedangkan grafik akumulasi ukuran butir umumnya memperlihatkan dominasi mekanisme transportasi dilatasi dan traksi daripada suspensi. Secara umum fosil yang terkandung dalam endapan tsunami Mentawai sangat jarang, namun sedikit banyak telah memberikan informasi seberapa dalam gelombang tsunami mulai menggerus lantai samudera dan memindahkannya ke darat, misalnya dengan ditemukannya fosil bentonik Sponge spicule yang melimpah, menunjukkan asal lingkungan laut dangkal dengan kedalaman laut 20-100 m. Kata kunci: Tsunami Mentawai 2010, endapan tsunami, analisis besar butir, identifikasi fosil.

scholarly journals Tsunami level disaster based on simulation scenario of earthquake modeling and seismicity in South Bali 2010-2018

2019 ◽  
Vol 2 (1) ◽  
pp. 36-41
Author(s):  
Fatmawati Fatmawati ◽  
I Made Yuliara ◽  
Ganis Riandhita ◽  
Febriyanti Jia Kelo ◽  
Audrey Vellicia ◽  
...  
Keyword(s):  
Arrival Time ◽  
Tsunami Hazard ◽  
Tsunami Modeling ◽  
Tsunami Waves ◽  
Average Value ◽  
The North ◽  
Simulation Scenario ◽  
Run Up ◽  
Hazard Level ◽  
Tsunami Run Up

Bali is one of the areas prone to earthquakes and tsunamis because it is located in the meeting area of ??two plates namely the Eurasian and Indo-Australian plates located in the south of Bali and a back-arc trust zone located in the north of Bali. Research has been carried out on tsunami hazard level analysis based on scenario modeling and earthquake seismicity in southern Bali. This study uses earthquake data in January 2010 - July 2018. Tsunami prone areas in southern Bali are Klungkung district, Nusa Penida, Kuta beach, Sanur beach, Tabanan and Gianyar districts. The research conducted aims to determine the level of tsunami hazard by looking at the tsunami run up and arrival time in the southern region of Bali. This simulation model uses 1427 data which is then processed using Generic Mapping Tools (GMT) software so that seismicity maps are obtained, and tsunami modeling uses the Tsunami Observation and Simulation Terminal (TOAST) software. The results obtained from the tsunami modeling simulation in the form of altitude (run up) and tsunami wave arrival time (arrival time) which have an average value of 1,385 - 2,776 meters with an arrival time of 20-24 minutes. The tsunami hazard level is obtained in scenario A with a magnitude of 7.5 which has a maximum value of <1 meter (low) and scenario B with a magnitude of 7.8 has a maximum tsunami run-up value of 1-3 meters (medium) and in scenario C with a magnitude 8.0 has a maximum run-up of tsunami waves of 1 - 3 meters (medium).

scholarly journals Assessing local impacts of the A.D. 1700 Cascadia earthquake and tsunami using tree ring growth histories: A case study in South Beach, Oregon, U.S.A.

2021 ◽  
Author(s):  
Robert P. Dziak ◽  
Bryan A. Black ◽  
Yong Wei ◽  
Susan G. Merle
Keyword(s):  
Ground Truth ◽  
Cascadia Subduction Zone ◽  
The South ◽  
Old Growth ◽  
Tsunami Inundation ◽  
The North ◽  
Resolution Model ◽  
Local Impacts ◽  
Run Up ◽  
Tsunami Run Up

Abstract. We present a spatially focused investigation of the disturbance history of an old-growth Douglass fir stand in South Beach, Oregon for possible growth effects due to tsunami inundation caused by the A.D. 1700 Cascadia subduction zone earthquake. A high-resolution model of the 1700 tsunami run-up heights at South Beach, assuming an L sized earthquake, is also presented to better estimate the inundation levels several kilometers inland at the old-growth site. This tsunami model indicates the South Beach fir stand would have been subjected to local inundation depths from 0–10 m. Growth chronologies collected from the fir stand shows several trees experienced significant growth reductions before, during and several years after 1700, consistent with the tsunami inundation estimates. The +/-1–3 year timing of the South Beach disturbances are also consistent with disturbances previously observed at a Washington state coastal forest ~220 km to the north. Additional comparison of the South Beach chronologies with regional chronologies across Oregon indicates the South Beach stand growth was significantly and unusually lower in 1700. Moreover, the 1700 South Beach growth reductions were not the largest over the 110-year tree chronology at this location. with other disturbances likely caused by other climate drivers (e.g. drought or windstorms). Our study represents a first step in using tree growth history to ground-truth tsunami inundation models by providing site specific physical evidence.

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