Geologic evidence for two pre-2004 earthquakes during recent centuries near Port Blair, South Andaman Island, India
TL;DR: In this paper, the authors show that the A.D. 2004 Sumatra-Andaman earthquake was accompanied by ∼1 m of subsidence, which is consistent with two prior earthquakes, perhaps both from the past 400 yr.
Abstract: Coastal stratigraphy near Port Blair, Andaman Islands, where the A.D. 2004 Sumatra-Andaman earthquake was accompanied by ∼1 m of subsidence, provides evidence for two prior earthquakes, perhaps both from the past 400 yr. The first of these (event I) is marked by an abrupt mud-over-peat contact best explained by subsidence similar to that in 2004. Event II is evidenced by an overlying chaotic layer composed of mud clasts in a sandy matrix that is connected with feeder dikes. These mud clasts, probably produced by liquefaction, are capped by laminated sand and mud that we ascribe to an event II tsunami. Radiocarbon ages of plant remains in the peat give discordant ages in the range 100 B.C. to A.D. 1950. Event I probably resembled the 2004 Sumatra-Andaman earthquake in that it was accompanied by subsidence (as much as 1 m) but not by strong shaking near Port Blair. If event II was the A.D. 1762 Arakan earthquake, the laminated sand and mud provide the first evidence that this earthquake was associated with a tsunami.
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TL;DR: In this article, microfossil habitat preferences and taphonomic character are used to constrain sediment provenance and identify overwash deposits, and how this information can be used to reconstruct the recurrence of tsunamis and storms.
98 citations
Cites background from "Geologic evidence for two pre-2004 ..."
...Marinemicrofossils often dominate tsunamioverwashdeposits because of the landward transport and deposition of scoured marine sediment (e.g., Dominey-Howes et al., 2000; Mamo et al., 2009; Goff et al., 2012; Tanaka et al., 2012)....
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TL;DR: In this article, the authors presented an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia, and demonstrated that at least 11 prehistoric tsunamis struck the Aceh coast between 7, 400 and 2,900 years ago.
Abstract: The devastating 2004 Indian Ocean tsunami caught millions of coastal residents and the scientific community off-guard. Subsequent research in the Indian Ocean basin has identified prehistoric tsunamis, but the timing and recurrence intervals of such events are uncertain. Here we present an extraordinary 7,400 year stratigraphic sequence of prehistoric tsunami deposits from a coastal cave in Aceh, Indonesia. This record demonstrates that at least 11 prehistoric tsunamis struck the Aceh coast between 7,400 and 2,900 years ago. The average time period between tsunamis is about 450 years with intervals ranging from a long, dormant period of over 2,000 years, to multiple tsunamis within the span of a century. Although there is evidence that the likelihood of another tsunamigenic earthquake in Aceh province is high, these variable recurrence intervals suggest that long dormant periods may follow Sunda megathrust ruptures as large as that of the 2004 Indian Ocean tsunami.
94 citations
TL;DR: In the last ten years, seismology and tsunami sciences as well as tsunami disaster risk reduction have significantly developed as discussed by the authors, which includes implementation of earthquake early warning, real-time estimation of earthquake source parameters and tsunami potential, paleoseismological studies on past earthquakes and tsunamis, studies of probable maximum size, recurrence variability, and long-term forecast of large earthquakes in subduction zones.
Abstract: The December 2004 Indian Ocean tsunami was the worst tsunami disaster in the world’s history with more than 200,000 casualties. This disaster was attributed to giant size (magnitude M ~ 9, source length >1000 km) of the earthquake, lacks of expectation of such an earthquake, tsunami warning system, knowledge and preparedness for tsunamis in the Indian Ocean countries. In the last ten years, seismology and tsunami sciences as well as tsunami disaster risk reduction have significantly developed. Progress in seismology includes implementation of earthquake early warning, real-time estimation of earthquake source parameters and tsunami potential, paleoseismological studies on past earthquakes and tsunamis, studies of probable maximum size, recurrence variability, and long-term forecast of large earthquakes in subduction zones. Progress in tsunami science includes accurate modeling of tsunami source such as contribution of horizontal components or “tsunami earthquakes”, development of new types of offshore and deep ocean tsunami observation systems such as GPS buoys or bottom pressure gauges, deployments of DART gauges in the Pacific and other oceans, improvements in tsunami propagation modeling, and real-time inversion or data assimilation for the tsunami warning. These developments have been utilized for tsunami disaster reduction in the forms of tsunami early warning systems, tsunami hazard maps, and probabilistic tsunami hazard assessments. Some of the above scientific developments helped to reveal the source characteristics of the 2011 Tohoku earthquake, which caused devastating tsunami damage in Japan and Fukushima Dai-ichi Nuclear Power Station accident. Toward tsunami disaster risk reduction, interdisciplinary and trans-disciplinary approaches are needed for scientists with other stakeholders.
73 citations
Cites background from "Geologic evidence for two pre-2004 ..."
...[27–29], the Andaman and Nicobar Islands [30,31] and...
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...Seismological data indicate that earthquakes with M 7.5 and 7.9 occurred in the Nicobar Islands and an M 7.7 earthquake occurred in the Andaman Islands in 1941 [23]....
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...The last earthquake was estimated to have occurred around AD 1300–1450 in Thailand, AD 1290–1400 in Sumatra, AD 1250–1450 near the Andaman and Nicobar Islands, post AD 1600 in South Andaman Island, and around AD 1020–1160 along the Indian coast....
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...Paleoseismological studies of tsunami deposits have been conducted since 2004 in Sumatra Island [26], Thailand [27–29], the Andaman and Nicobar Islands [30,31] and India [32]....
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...These past earthquakes had been considered as the maximum earthquakes in the Andaman and Nicobar Islands....
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TL;DR: In this paper, the authors divide earthquake cycle behavior into four major classes that have different implications for seismic hazard and fault mechanics: 1) quasi-periodic similar ruptures, 2) clustered similar rupture, 3) clustered complementary ruptures/rupture cascades, and 4) superimposed cycles.
64 citations
TL;DR: In this article, the authors explore qualitative and quantitative techniques that employ the relation between diatoms and salinity, tidal elevation, and life form to reconstruct records of vertical land-level change associated with large earthquakes; and identify anomalous sand and silt beds deposited by tsunamis.
62 citations
References
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University of California, Santa Cruz1, University of California, Los Angeles2, California Institute of Technology3, Pennsylvania State University4, Harvard University5, New Mexico Institute of Mining and Technology6, University of Arizona7, Miami University8, University of Wisconsin-Madison9, Incorporated Research Institutions For Seismology10, United States Geological Survey11
TL;DR: Tsunami and geodetic observations indicate that additional slow slip occurred in the north over a time scale of 50 minutes or longer, and fault slip of up to 15 meters occurred near Banda Aceh, Sumatra, but to the north, along the Nicobar and Andaman Islands, rapid slip was much smaller.
Abstract: The two largest earthquakes of the past 40 years ruptured a 1600-kilometer-long portion of the fault boundary between the Indo-Australian and southeastern Eurasian plates on 26 December 2004 [seismic moment magnitude (Mw) = 9.1 to 9.3] and 28 March 2005 (Mw = 8.6). The first event generated a tsunami that caused more than 283,000 deaths. Fault slip of up to 15 meters occurred near Banda Aceh, Sumatra, but to the north, along the Nicobar and Andaman Islands, rapid slip was much smaller. Tsunami and geodetic observations indicate that additional slow slip occurred in the north over a time scale of 50 minutes or longer.
1,030 citations
TL;DR: The 26 December 2004 Sumatra-Andaman earthquake initiated slowly, with small slip and a slow rupture speed for the first 40 to 60 seconds, then the rupture expanded at a speed of about 2.5 kilometers per second toward the north northwest, extending 1200 to 1300 kilometers along the Andaman trough as discussed by the authors.
Abstract: The 26 December 2004 Sumatra-Andaman earthquake initiated slowly, with small slip and a slow rupture speed for the first 40 to 60 seconds. Then the rupture expanded at a speed of about 2.5 kilometers per second toward the north northwest, extending 1200 to 1300 kilometers along the Andaman trough. Peak displacements reached ∼15 meters along a 600-kilometer segment of the plate boundary offshore of northwestern Sumatra and the southern Nicobar islands. Slip was less in the northern 400 to 500 kilometers of the aftershock zone, and at least some slip in that region may have occurred on a time scale beyond the seismic band.
660 citations
TL;DR: In this article, modern subaerial sand beds deposited by major tsunamis and hurricanes were compared at trench, transect, and sub-regional spatial scales to evaluate which attributes are most useful for distinguishing the two types of deposits.
598 citations
Pontifical Catholic University of Valparaíso1, University of Washington2, National Institute of Advanced Industrial Science and Technology3, University of Concepción4, Pontifical Catholic University of Chile5, National Oceanic and Atmospheric Administration6, Centre for Earth Science Studies7, Indian Institute of Technology Kanpur8
TL;DR: This work uses buried soils and sand layers as records of tectonic subsidence and tsunami inundation at an estuary midway along the 1960 rupture as evidence that such long intervals were indeed typical of the last two millennia.
Abstract: It is commonly thought that the longer the time since last earthquake, the larger the next earthquake's slip will be. But this logical predictor of earthquake size, unsuccessful for large earthquakes on a strike-slip fault, fails also with the giant 1960 Chile earthquake of magnitude 9.5 (ref. 3). Although the time since the preceding earthquake spanned 123 years (refs 4, 5), the estimated slip in 1960, which occurred on a fault between the Nazca and South American tectonic plates, equalled 250-350 years' worth of the plate motion. Thus the average interval between such giant earthquakes on this fault should span several centuries. Here we present evidence that such long intervals were indeed typical of the last two millennia. We use buried soils and sand layers as records of tectonic subsidence and tsunami inundation at an estuary midway along the 1960 rupture. In these records, the 1960 earthquake ended a recurrence interval that had begun almost four centuries before, with an earthquake documented by Spanish conquistadors in 1575. Two later earthquakes, in 1737 and 1837, produced little if any subsidence or tsunami at the estuary and they therefore probably left the fault partly loaded with accumulated plate motion that the 1960 earthquake then expended.
471 citations
TL;DR: In this paper, the authors present a method to solve the problem of homonymity in the context of homophysics, and no abstracts available, but no abstract available.
Abstract: Abstract No abstract available.
439 citations
"Geologic evidence for two pre-2004 ..." refers methods in this paper
...To infer autecology of diatom species, we referred standard reference for freshwater and brackish diatoms (e.g., Vos and deWolf, 1993; Witkowski et al., 2000)....
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