Accommodation space, relative sea level, and the archiving of paleo-earthquakes along subduction zones

Geology
By: , and 

Links

Abstract

The spatial variability of Holocene relative sea-level (RSL) change influences the capacities of coastal environments to accommodate a sedimentary record of paleoenvironmental change. In this study we couch a specific investigation in more general terms in order to demonstrate the applicability of the relative sea-level history approach to paleoseismic investigations. Using subsidence stratigraphy, we trace the different modes of coastal sedimentation over the course of time in the eastern Indian Ocean where RSL change evolved from rapidly rising to static from 8000 yr ago to present. Initially, the coastal sites from the Aceh, Sumatra, coastal plain, which are subject to repeated great earthquakes and tsunamis, built up a sedimentary sequence in response to a RSL rise of 1.4 mm/yr. The sequence found at 2 sites 8 km apart contained 3 soils of a mangrove origin (Rhizophora,Bruguiera/Ceriops, Avicennia pollen, and/or intertidal foraminifera) buried by sudden submergence related to coseismic subsidence and 6 tsunami sands that contain pristine subtidal and planktic foraminifera. After 3800 cal yr B.P. (years before A.D. 1950), sea level stabilized and remained such to the present. The stable relative sea level reduced accommodation space in the late Holocene, suggesting that the continued aggradation of the coastal plain was a consequence of periodic coastal inundation by tsunamis.

Publication type Article
Publication Subtype Journal Article
Title Accommodation space, relative sea level, and the archiving of paleo-earthquakes along subduction zones
Series title Geology
DOI 10.1130/G36706.1
Volume 43
Issue 8
Year Published 2015
Language English
Publisher Geological Society of America
Contributing office(s) Eastern Geology and Paleoclimate Science Center
Description 4 p.
First page 675
Last page 678
Google Analytic Metrics Metrics page
Additional publication details