Satake Tsunamis

Case Studies and Recent Developments
1. Auflage 2005
ISBN: 978-1-4020-3331-5
Verlag: Springer Netherland
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 23, 347 Seiten, eBook

Reihe: Advances in Natural and Technological Hazards Research

This book contains 20 papers reflecting the state-of-the-art tsunami research. Most of them were presented at the two international meetings held in 2003: the 21st International Tsunami Symposium, held on July 9 and 10th as a part of IUGG general assembly in Sapporo, Japan, and an International Workshop on Tsunamis in the South Pacific, held on September 25 and 26th in Wellington, New Zealand. More recent work, including the field survey report of the Tokachi-oki earthquake tsunami of September 26, 2003, is also included. Synolakis and Okall summarize the survey results of International Tsunami Survey Teams, as well as seismological and numerical modelling studies of 15 tsunami events occurred between 1992 and 2002. In this active decade of tsunami disasters, the tsunami community has learned how to organize ITST, describe, document and share the results of surveys. The authors also propose a method to discriminate the seismic tsunamis from landslide tsunamis based on the observed runup heights, and demonstrate it for the recent tsunamis. Power et al. report the tsunamis generated by the 2003 Fiordland, New Zealand, earthquake (M 7. 2). This earthquake generated two kinds of tsunamis; a local large (4-5 m) tsunami generated by rockslide in a sound, and a smaller tsunami generated by earthquake fa aulting and detected on tide gauges in Australia. Three papers discuss volcanic tsunamis in the western Pacific region. Nishimura et al. report the tsunami from the 1994 eruption of Rabaul volcanoes.

Zielgruppe

Research

Autoren/Hrsg.

Satake, Kenji

Inhaltsverzeichnis

Case Studies.- 1992–2002: Perspective on a Decade of Post-Tsunami Surveys.- The Fiordland Earthquake and Tsunami, New Zealand, 21 August 2003.- Timing and Scale of Tsunamis Caused by the 1994 Rabaul Eruption, East New Britain, Papua New Guinea.- Analysis of Tide-Gauge Records of the 1883 Krakatau Tsunami.- Model of Tsunami Generation by Collapse of Volcanic Eruption: The 1741 Oshima-Oshima Tsunami.- Tsunami Resonance Curve from Dominant Periods Observed in Bays of Northeastern Japan.- Delayed Peaks of Tsunami Waveforms at Miyako from Earthquakes East off Hokkaido.- Field Survey of the 2003 Tokachi-Oki Earthquake Tsunami and Simulation at the Ootsu Harbor Located at the Pacific Coast of Hokkaido, Japan.- Variability Among Tsunami Sources in the 17th–21st Centuries Along the Soutehrn Kuril Trench.- Holocene Tsunami Traces on Kunashir Island, Kurile Subduction Zone.- Distribution of Cumulative Tsunami Energy from Alaska-Aleutians to Western Canada.- Recent Developments.- Mapping the Possible Tsunami Hazard as the First Step Towards a Tsunami Resistant Community in Esmeraldas, Ecuador.- Progresses in the Assessment of Tsunami Genesis and Impacts around the Portuguese Coasts.- Quick Tsunami Forecasting Based on Database.- Adjoint Inversion of the Source Parameters of Near-Shore Tsunamigenic Earthquakes.- Experimental Design for Solid Block and Granular Submarine Landslides: A Unified Approach.- Effects of Coastal Forest on Tsunami Hazard Mitigation — A Preliminary Investigation.- Fluid Force on Vegetation Due to Tsunami Flow on a Sand Spit.- Hydro-Acoustic Monitoring on the Kamchatka Shelf: A Possibility of Early Location of Oceanic Earthquake and Local Tsunami Warning.- Electromagnetic Tsunami Monitoring: Theory and Recommendations.

Leseproben

HOLOCENE TSUNAMI TRACES ON KUNASHIR ISLAND, KURILE SUBDUCTION ZONE (p. 171-172)

A.YA. ILIEV1, V.M. KAISTRENKO1, E.V. GRETSKAYA1, E.A. TIKHONCHUK1, N.G. RAZJIGAEVA2, T.A. GREBENNIKOVA2, L.A. GANZEY2 AND A.A. KHARLAMOV3

1 Institute of Marine Geology and Geophysics FEB RAS, Yuzhno-Sakhalinsk, Russia
2 Pacific Institute of Geography FEB RAS, Vladivostok, Russia y
3 P.P. Shirshov Institute of Oceanology RAS, Moscow, Russia

The paper presents the detailed study of sediments deposited by middle-late Holocene tsunami in the Pacific Ocean at the Okhotsk Sea area and Izmena Bay coast of Kunashir Island. Seventeen thin sand-layers were found to be intercalated within peat of lacustrine deposits. Field data, grain-size composition, and biostratigraphical data allow interpretation of them as paleotsunami traces. Age of the sand-sheet was based a on radiocarbon dating and tephrostratigraphy. Diatoms helped identify the tsunami deposits’ origins and confirm that the sands had a marine source, and establish the landward extent of tsunami inundation. Tsunami deposits contain more contents of neritic and oceanic diatoms than marine units deposited during Holocene transgressions. The sand layers were deposited by tsunami with a maximal run-up more than 7 m, and penetration inland more the 2.5 km. The time period relating to the found tsunami deposits is 6,000–7,000 years. Correlation of tsunami events of Kunashir, Iturup Island, and Eastern Hokkaido have been done.

Key words:
tsunami deposits, diatoms, inundation limit, Holocene, Southern Kuriles.

1 Introduction

Located in one of the most active seismic regions of North-Western Pacific, Kunashir Island is known to have several great earthquakes during historical times, some of which were accompanied by tsunami. Tsunami waves produced by the 4 October 1994 earthquake, the epicenter of which was located near Shikotan Island, had the heights up to 8.7 m above mean sea level on the eastern coast of the Kunashir Island (Korolyov et al., 1997). Catastrophic tsunami are rare events, and historical data does not include reliable estimates of their frequency, impact on natural environments, and their effect on coastal development and tsunami hazard prognoses. The modern approach to such problems supposes a search and analysis of geological traces of paleotsumani that allows a reconstruction of the chronology of catastrophic tsunami at the Holocene, estimate their frequency and intensity, and spatial distribution on the basis of the correlation of tsunami deposits of contiguous areas. Evidence of strong tsunamis and pre-historic earthquakes in this region has been found in Iturup Island (Bulgakov et al., 1995) and Eastern Hokkaido (Nanayama et al., 2000, 2003, Sawai, 2002, Hirakawa et al., 2003).

Existing tsunami catalogues contain the tsunami data for the Kunashir Island coast only since 1958. Such a short tsunami history of this region doesn’t allow the creation of a good model for the description of the tsunami activity. However the needed tsunami data can be found in Holocene coastal sequences. Holocene peatlands, widespread along the Pacific coast of Kunashir and within low isthmuses are informative objects for paleotsunami study. Other useful objects for examination are numerous modern, and ancient, coastal lakes in the region. The paleotsunami study includes searches of their traces in Holocene sequences and, afterwards, the identification of their origins by diatom analysis and sedimentological methods.

Diatoms are particularly useful in studies of paleotsunami deposits because different species are found in freshwater than in brackish-marine environments, and, therefore, can be used to identify past marine incursion, including those associated with tsunami (Minoura and Nakata, 1994, Hemphill-Haley, 1996, Nanayama et al., 2000, 2003, Nishimura et al., 2000, Sawai, 2002). Frequent volcanic activity on Kunashir Island are main factors for favorable diatoms development in different freshwater and marine environments (Grebennikova, 2000). The presence of marine and brackish diatoms among freshwater assemblages in thin sand layers indicates short-time marine influence, which can be connected to storm-surge or tsunami. Marine diatoms from these deposits are rare and most valves are fragmented (Sawai, 2001, 2002). Diatom assemblages from marine deposits that formed during transgressions are characterized by high abundance and high diversity of marine species and well-preserved valves. Ecological parameters of such diatom assemblages are typical for climatic warming. Thickness of transgressive sequences is, as a rule, significant. This paper presents the result of reconnaissance work, some stratigraphical data, and other evidence, for a several tsunami that occurred about 6,000-7,000 years BP on the South Kurile region.