scholarly journals Tracing woody-organic tsunami deposits of the 2011 Tohoku-oki event in Misawa (Japan)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Piero Bellanova ◽  
Mike Frenken ◽  
Yuichi Nishimura ◽  
Jan Schwarzbauer ◽  
Klaus Reicherter
Keyword(s):  
Analytical Data ◽  
Control Area ◽  
Organic Layer ◽  
Sandy Sediment ◽  
Tsunami Deposit ◽  
Organic Fraction ◽  
Tsunami Deposits ◽  
Tsunami Inundation ◽  
Sandy Deposit ◽  
Sand Sheets

AbstractWith a minimum of three reported waves, the 2011 Tohoku-oki tsunami’s destructive force caused massive damage along the northern Japanese Aomori coast. At Misawa the coastal control area was inundated up to 550 m inland and sandy sediment remnants can be traced to c. 350 m (c. 61–63% of the maximum inundation) from the shoreline. Linking the discovery of floatable plastic objects within a woody and organic layer to our analytical data lead to the detection of a yet undocumented woody-organic tsunami deposit first appearing on top of the sandy deposit but then reaching even further inland (approx. 69–72% of the max. inundation). By this observation our understanding of the documented part of the tsunami inundation may be improved. As a consequence, sand sheets of historic and paleo-tsunamis represent minimum estimates for the coastal inundation and underestimation may be reduced by addressing the woody and organic fraction of a tsunami’s inundation.

Invisible tsunami deposits – the Misawa example, Japan

2021 ◽  
Author(s):  
Piero Bellanova ◽  
Mike Frenken ◽  
Yuchi Nishimura ◽  
Jan Schwarzbauer ◽  
Klaus Reicherter
Keyword(s):  
Analytical Data ◽  
Field Work ◽  
Organic Layer ◽  
Natural Environments ◽  
Sandy Sediment ◽  
Tsunami Deposit ◽  
Critical Observation ◽  
Sandy Deposit ◽  
Sand Sheets ◽  
Northern Japan

<p>With at least three reported waves, the 2011 Tohoku-oki tsunami’s destructive force caused massive damage along the Aomori coastline in northern Japan. At Misawa the coastal area was inundated up to 550 m inland and sandy sediment remnants can be traced to c. 350 m (c. 61-63% of the maximum inundation) from the shoreline.</p><p>The discovery of a floatable plastic object within a previously inconspicuous woody and organic layer in connection to our analytical data lead to the detection of a yet undocumented ‘invisible’ tsunami deposit. This layer is first appearing on top of the sandy deposit but then reaching even further inland (approx. 69-72% of the max. inundation). Initially the organic and woody layer was not evident during early stages of the field work and this would have been unchanged without the discovery of the floatable plastic particle embedded within the deposit. That critical observation was the turning point for the interpretation of the layer’s origin and thus our understanding of processes during the Tohoku-oki tsunami at the Aomori coast near Misawa harbor. Overall, may the first recognition of this woody-organic and up to now ‘invisible’ layer lead to an improvement in the understanding of tsunami processes and their sedimentological characteristics. Further, may the knowledge obtained from these types of deposits be transferred to and improve paleo-tsunami investigations, especially in rural natural environments, as sand sheets of historic and paleo-tsunamis represent minimum estimates for the coastal inundation and potential underestimations may be reduced by addressing the ‘invisible’ fraction of a tsunami’s inundation.</p>

scholarly journals Late Miocene to Pliocene Tsunami Deposits in Tegal Buleud, South Sukabumi, West Java, Indonesia

2019 ◽  
Vol 13 (12) ◽  
pp. 80
Author(s):  
Yan Rizal ◽  
Aswan Aswan ◽  
Jahdi Zaim ◽  
Mika R. Puspaningrum ◽  
Wahyu D. Santoso ◽  
...  
Keyword(s):  
Late Miocene ◽  
Flame Structure ◽  
Tectonic Activity ◽  
Tsunami Deposit ◽  
Size Distributions ◽  
Volcanic Island ◽  
Tsunami Deposits ◽  
West Java ◽  
Foraminiferal Assemblage ◽  
Grain Size Distributions

Java is a volcanic island arc formed by the northwards subduction of the Eurasian and Australian Plates. Due to this active subduction, Java has been frequently shocked by earthquakes, which might induce tsunami events. However, there are hardly any ancient geological records of tsunami events in the area. This study aims to determine the presence and to identify sedimentary characters of tsunami deposit in Tegal Buleud, South Sukabumi, West Java. In the study area, there were 4 tsunami layers which were found as thin intercalation within the claystone layer of the Bentang Formation. Those paleotsunami deposits characterized by the occurrence of irregular/disturbed structure such as siltstone rip up, clay clasts, and flame structure occur in normal graded bedding sandstone layer. The grain-size distributions show bimodal and multimodal patterns, with mixing of marine microfossils from inner and middle neritic. The planktonic foraminiferal assemblage indicates that the age of the sediment comparable to N19 (equivalent to Late Miocene - Early Pliocene, at about 5.33 – 3.6 Ma), suggested that these paleotsunami layers were deposited due to the Mio-Pliocene tectonic activity. All the paleotsunami deposits found in Study area are the first and oldest tsunami deposit recorded in Java even in Indonesia. With the discovery of the previously unexplored Late Miocene to Pliocene tsunami deposits found in the study area, the result of this study can be used as a reference for the identification of the Tertiary tsunami deposits present in other parts of Indonesia.

Tsunami Deposits Beneath Tidal Marshes on Northwestern Vancouver Island, British Columbia

1997 ◽  
Vol 48 (2) ◽  
pp. 192-204 ◽  
Author(s):  
Boyd E. Benson ◽  
Kurt A. Grimm ◽  
John J. Clague
Keyword(s):  
British Columbia ◽  
Plate Boundary ◽  
Vancouver Island ◽  
Tidal Marshes ◽  
Tsunami Source ◽  
Cascadia Subduction Zone ◽  
Tsunami Deposits ◽  
The North ◽  
Sand Sheet ◽  
Sand Sheets

AbstractTwo sand sheets underlying tidal marshes at Fair Harbour, Neroutsos Inlet, and Koprino Harbour on the northwestern coast of Vancouver Island, British Columbia, were probably deposited by tsunamis. The sand sheets become thinner and finer-grained landward, drape former land surfaces, contain marine microfossils, are locally graded or internally stratified, and can be correlated with earthquakes that generated tsunamis in the region. 137Cs dating and historical accounts indicate that the upper sand sheet was deposited by the tsunami from the great Alaska earthquake in 1964. Radiocarbon ages on plant fossils within and on top of the lower sand sheet show that it was deposited sometime after about A.D. 1660. We attribute the lower sand sheet to a tsunami from the most recent plate-boundary earthquake on the Cascadia subduction zone about 300 yr ago, extending the documented effects of this earthquake north of the Nootka fault zone. The 1964 tsunami deposits differ little in thickness and continuity among the three marshes. In contrast, the lower sand sheet becomes thinner and less continuous to the north, implying a tsunami source south of the study area.

scholarly journals Reconstruction of Tsunami Occurrence on Okushiri Island, Southwestern Hokkaido, Japan

2021 ◽  
Author(s):  
Atsushi Urabe ◽  
Yoshihiro Kase ◽  
Gentaro Kawakami ◽  
Kenji Nishina ◽  
Yasuhiro Takashimizu ◽  
...  
Keyword(s):  
Japan Sea ◽  
Tsunami Deposit ◽  
Fault Activity ◽  
Tsunami Deposits ◽  
Tectonic Zone ◽  
Tectonic Plates ◽  
Eastern Margin ◽  
The North ◽  
The Japan Sea ◽  
Okushiri Island

Abstract The eastern margin of the Japan Sea is located along an active convergent boundary between the North American and Eurasian tectonic plates. Okushiri Island, which is situated off the southwest coast of Hokkaido, is located in an active tectonic zone where many active submarine faults are distributed. Studying the records of past tsunamis on Okushiri Island is important for reconstructing the history and frequency of fault activity in this region, as well as the history of tsunamis in the northern part of the eastern margin of the Japan Sea. Five tsunami deposit horizons have been identified previously on Okushiri Island, including that of the 1741 tsunami, which are interbedded in the coastal lowlands and Holocene terraces. However, these known tsunami deposits date back only ~3,000 years. A much longer record of tsunami occurrence is required to consider the frequency of submarine fault activity. In this study, we cored from 7 to 25 m depth in the Wasabiyachi lowland on the southern part of Okushiri Island, where previous studies have confirmed the presence of multiple tsunami deposits on peat layer surfaces. The results indicate that the Wasabiyachi lowland comprises an area that was obstructed by coastal barriers between the lowland and the coast at ~8.5 ka and consists of muddy sediment and peat layers formed in lagoons and floodplains, respectively. In addition, event deposits and 15 tsunami horizons were observed among the turbidites and peat layers, dating back as far as 3,000 years. Combined with previous findings, Okushiri Island has sustained 20 tsunami events between ~7.5 ka and the present. These findings are critical for investigating the activities of submarine faults off the southwestern coast of Hokkaido, as well as for determining tsunami risks along the coast of the Japan Sea between North Tohoku and Hokkaido.

scholarly journals Numerical Simulations of the 2004 Indian Ocean Tsunami Deposits Thicknesses and Emplacements

2018 ◽  
Author(s):  
◽  
Musa Al'ala ◽  
Hermann M. Fritz ◽  
Mirza Fahmi ◽  
Teuku Mudi Hafli
Keyword(s):  
Sediment Transport ◽  
Indian Ocean ◽  
Numerical Simulations ◽  
Field Data ◽  
Numerical Models ◽  
Indian Ocean Tsunami ◽  
Tsunami Deposit ◽  
Field Observations ◽  
Tsunami Deposits ◽  
2004 Indian Ocean Tsunami

Abstract. After more than a decade of recurring tsunamis, identification of tsunami deposits, a part of hazard characterization, still remains a challenging task not fully understood. The lack of sufficient monitoring equipment and rare tsunami frequency are among the primary obstacles that limit our fundamental understanding of sediment transport mechanisms during a tsunami. The use of numerical simulations to study tsunami-induced sediment transport was rare in Indonesia until the 2004 Indian Ocean tsunami. This study aims to couple two hydrodynamic numerical models in order to reproduce tsunami-induced sediment deposits, i.e., their locations and thicknesses. Numerical simulations were performed using the Cornell Multi-Grid Coupled Tsunami Model (COMCOT) and Delft3D. This study reconstructed tsunami wave propagation from its source using COMCOT, which was later combined with Delft3D to map the location of the tsunami deposits and calculate their thicknesses. Two Dimensional-Horizontal (2DH) models were used as part of both simulation packages. Lhoong, in the Aceh Besar District, located approximately 60 km southwest of Banda Aceh, was selected as the study area. Field data collected in 2015 and 2016 validated the forward modeling techniques adopted in this study. However, agreements between numerical simulations and field observations were more robust using data collected in 2005, i.e., just months after the tsunami (Jaffe et al., 2006). We conducted pit (trench) tests at select locations to obtain tsunami deposit thickness and grain size distributions. The resulting numerical simulations are useful when estimating the locations and the thicknesses of the tsunami deposits. The agreement between the field data and the numerical simulations is reasonable despite a trend that overestimates the field observations.

Identification of suspected paleotsunami deposits study from Karapyak Beach, Pangandaran area, West Jawa, Indonesia

2021 ◽  
Vol 36 (2) ◽  
Author(s):  
Aswan Aswan ◽  
Yan Rizal
Keyword(s):  
Thin Layer ◽  
Energy Flow ◽  
Fine Sand ◽  
High Energy ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Tsunami Deposit ◽  
Tsunami Deposits ◽  
Rock Fragments ◽  
Coarse Grains

Identifying and constraining palaeotsunami deposits can be a vital tool for establishing the periodicity of earthquakes and their associated tsunami events beyond the historical records. However, the deposits can be difficult to establish and date. In this study we used the characteristics of the 2006 Pangandaran tsunami deposit as a reference for identification of paleotsunami deposits in Karapyak Beach, Pangandaran area, West Java, Indonesia. Similar to the 2006 Pangandaran tsunami deposit, the Karapyak Beach paleotsunami deposit is characterized by light brown loose sand materials overlying a dark brown paleosoil layer with erosional contact. A thin layer that varies in thickness is locally found right above the erosional contact, with non-laminated coarser grain in the lower part that gradually change into medium to fine sand-sized in upper part. The base of the lower part is rich with broken mollusc shells and corals, and the mid-top of the lower part may contain several intact molusc shells and corals, rock fragments and anthropogenic products (rooftile). Those types of fragments are absent in the upper part of the thin layer. Grain size analysis shows a mixture of fine and coarse grains in the lower part of 2006 tsunami deposits as well as in the suspected paleotsunami deposits, suggesting uprush high energy flow during sedimentation. Fining upward sequence above mixed grain layers reflects waning flow or pre-backwash deposition. Foraminifera analysis also shows a mixture of shallow and deep marine foraminifera in the two deposits. Based on the characteristics of the 2006 tsunami deposits, there are at least four identified paleotsunami deposits at Karapyak Beach, Pangandaran area.

Organic geochemical analysis of multiple tsunami deposits of the last century at the Aomori coast (Northern Japan)

2020 ◽  
Author(s):  
Mike Frenken ◽  
Piero Bellanova ◽  
Yuichi Nishimura ◽  
Jan Schwarzbauer ◽  
Klaus Reicherter
Keyword(s):  
Soil Layer ◽  
Strong Increase ◽  
Coastal Protection ◽  
Tsunami Deposit ◽  
Field Site ◽  
Tsunami Deposits ◽  
Anthropogenic Markers ◽  
Eyewitness Reports ◽  
Polycyclic Aromatic ◽  
Northern Japan

<p>Japan, more precisely, the eastern coastal areas of Honshu, are one of the most affected areas of tsunamis in the world. Major events within the last century were three Sanriki-oki tsunamis (1896, 1933, 1968), and the most recent 2011 Tohoku-oki tsunami, triggered by the 9.1 M<sub>W</sub> Tohoku-oki earthquake, which caused massive damage along the coastlines.</p><p>The 2011 Tohoku-oki tsunami overtopped the coastal defense walls with waves of 6-10 m height along the shores of the Aomori Prefecture in Northern Japan. The inundation reached up to 550 m inland, however, sandy tsunami deposits are limited to 250 – 350 m of the total inundation distance. At the field site of Misawa Harbor the well-preserved identifiable tsunami remains show up to 18 cm thick sand layers with sedimentary features, such as fining upward sequences, mud caps and rip-up clasts. The sandy deposits were enclosed in the soil of the coastal protection forest. Along with the sedimentary record of the tsunami, the use of organic geochemical indicators can provide a better understanding of the extend and processes, such as the deposition of tsunami layers and the backwash, of the inundation by the 2011 Tohoku-oki tsunami. The devastating damages caused by the interaction of tsunami and earthquake released pollutants associated as biological and anthropogenic markers. These released pollutants give the tsunami deposit an unique geochemical signature, that is distinguishable from the background sedimentation. Organic-geochemical results reveal a strong increase of anthropogenic (polycyclic aromatic hydrocarbons, pesticides and chlorinated compounds) and a variation of biological markers (i.e. n-alkanes, fatty acids) in the 2011 tsunami deposit close to the fishery port. During the analysis of the samples, another variation of biomarker and anthropogenic marker were identified right below the soil layer of the current forest. This layer is as well distinguishable from the paleo-dune that marks the lowest sedimentological unit at the field site. This differentiation shows the likely impact of a historical Sanriki-oki tsunami (1896, 1933 or 1968). These organic geochemical results in combination with local eyewitness reports of the tsunamis and lead to the assumption that the sedimentary archive of the Aomori coastline contains and preserved at two or more tsunami events of the last century.</p><p>The inclusion of organic geochemical markers to expand the characterizing and identifying proxies used in tsunami research are important to get a better understanding of the processes and deposition during tsunamis. Furthermore, this method can detect tsunami deposits beyond the visible recognizability of sedimentological identification of tsunami deposits and therefore can serve as a blue-print for historical and paleo-tsunami studies, as most of them only rely on visible sand deposits as marker for inundation distances from the beach. The high-resolution geochemical application can gain more information than standard techniques, like the identification of the “invisible” tsunami layer exceeding the limits of sandy deposits or the deposition in similar sedimentary textures, capturing a broader picture of the event.</p>

scholarly journals Tsunami deposits in Martinique related to the 1755 Lisbon earthquake

2017 ◽  
Author(s):  
Valérie Clouard ◽  
Jean Roger ◽  
Emmanuel Moizan
Keyword(s):  
Collaborative Research ◽  
Time Window ◽  
Oceanic Islands ◽  
Recurrence Time ◽  
Tsunami Deposit ◽  
Archaeological Remains ◽  
Tropical Islands ◽  
Tsunami Inundation ◽  
Lisbon Earthquake ◽  
Drainage Channels

Abstract. In order to assess tsunami hazard in oceanic islands, one needs to enlarge the observational time window by finding more evidence of past events. To that end, evidence of allochthonous deposits provides estimates of tsunami inundation, recurrence time and magnitude. However, in tropical islands, erosion due to the highly rainy climate generally prevents deposits to stay in place and when they are, relating them to a tsunami is not straightforward, as they can result either from a strong hurricane or from a tsunami. One notable exception concerns deposits sealed by subsequent events. In this paper, we present evidence of an anomalously thick two-layer tsunami deposit in an excavation in Martinique. Analysis of the archaeological remains indicate that it is related to the 1755 Lisbon tsunami. We explain the thickness of the deposit by a tsunami-induced bore in the mangrove drainage channels of Fort-de-France. Our results highlight the benefits of collaborative research involving geology and archaeology, indicate a way to improve our tsunami databases and further constrain the use of numerical modelling to predict paleo-tsunami deposit thickness.

A record of local storms and trans-Pacific tsunamis, eastern Banks Peninsula, New Zealand

The Holocene ◽  
2016 ◽  
Vol 27 (4) ◽  
pp. 496-508 ◽  
Author(s):  
Jai Donnelly ◽  
James Goff ◽  
Catherine Chagué-Goff
Keyword(s):  
New Zealand ◽  
Tsunami Deposit ◽  
Sediment Characteristics ◽  
Tsunami Deposits ◽  
The World ◽  
Lateral Extent ◽  
Storm Deposits ◽  
First Time ◽  
Grain Size Parameters ◽  
Tsunami Sediments

This study of five sand units at Lavericks Bay, New Zealand, reports on the sedimentary evidence for three trans-Pacific tsunamis and two local storms. The 1868 Arica, 1877 Iquique and 1960 Valdivia tsunamis from Chile were the largest distantly generated events in New Zealand’s history but have never before been identified at the same location. It is also the first time that the 1877 Iquique tsunami deposit has been found in New Zealand. Two further sand units were identified as local storm deposits laid down in 1869/1870 and 1929. The identification and chronology of these events were established through the use of geochemistry, palynology, diatoms, charcoal abundance and historical documents. Their relative magnitudes were estimated through the use of grain size parameters and lateral extent of the recognisable sand layers. The recognisable sandy tsunami deposits extend about 60% of the inundation distance, while the storm sediments are finer and less extensive. There were two notable geochemical differences between the storm and tsunami deposits. Both storm deposits had lower concentrations of marine proxy elements associated with lower Ca–Ti and Sr–Ba ratios. Other differences were noted between some of the tsunami and storm deposits such as rip-up clasts and sediment characteristics, but these were by no means unequivocal. It is possible that geochemistry may prove to be the only proxy capable of not only differentiating effectively between storm and tsunami sediments but also identifying the maximum inland extent of a deposit and of inundation. It is the ability to better understand the nature and extent of such catastrophic events through these subtle differences in event characteristics that will help improve risk management for coastlines around the world.

Sign in / Sign up

Export Citation Format

Share Document