Modern analogue to past coseismic ground uplift in North Andaman, IndiaShow others and affiliations
2021 (English)In: Catena (Cremlingen. Print), ISSN 0341-8162, E-ISSN 1872-6887, Vol. 205, article id 105471Article in journal (Refereed) Published
Abstract [en]
Dynamics of surface geological processes, triggered by coseismic ground uplift following the 2004 Sumatra-Andaman earthquake (M-w > 9.2), provide a modern analogue for assessing the paleoseismic significance of an enigmatic subsurface peat occurrence within beach sands in the western coast of North Andaman Island. The megathrust earthquake uplifted vast stretches of coastal intertidal zones to supratidal levels. As a result, intertidal flora, including mangroves, desiccated and perished. Mass mortality of the flora continued even three years after the earthquake and generated a large volume of forest debris. Coastal waves pushed the debris to the high tide line where the accumulated debris would be gradually buried, and would subsequently transform into linear peat bodies keeping a record of the seismic event in 2004. Accordingly, we have interpreted a linear strand-parallel peat occurrence in beach sand as a record of earlier mass mortality of plants likely associated with a coseismic ground uplift. Stable isotope studies indicate that local intertidal flora is the source of the peat organic matter. Moreover, the 1817 CE calibrated mean AMS radiocarbon age of the peat suggests recurrence of a megathrust earthquake in the Andaman subduction zone about 200 years ago.
Place, publisher, year, edition, pages
Elsevier, 2021. Vol. 205, article id 105471
Keywords [en]
Subduction zone, Coseismic uplift, Plant mortality, Peat, Stable isotopes, Radiocarbon dating
National Category
Ecology Earth and Related Environmental Sciences
Identifiers
URN: urn:nbn:se:oru:diva-93190DOI: 10.1016/j.catena.2021.105471ISI: 000659891800017Scopus ID: 2-s2.0-85107805325OAI: oai:DiVA.org:oru-93190DiVA, id: diva2:1582270
Note
Funding Agencies:
Department of Science & Technology (India)
Department of Science & Technology (DOST), Philippines
Honorary Scientist Scheme (2015-2018) of the National Academy of Sciences India
Department of Science & Technology (India) DST/INT/JSPS/P-232/2016
Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT)
Japan Society for the Promotion of Science 18KK0096
2021-07-302021-07-302025-01-31Bibliographically approved