Sedimentary evidence for a mid-Holocene iceberg-generated tsunami in a coastal lake, west Greenland
Loading...
Date
2015-12
Advisor
Editor
Journal Title
Journal ISSN
Volume Title
Publisher
Title alternative
Abstract
We report sedimentological evidence for a tsunami from a coastal lake at Innaarsuit, Disko Bugt (west Greenland), which was most likely generated by a rolling iceberg. The tsunami invaded the lake c. 6000 years ago, during a period of time when relative sea level (RSL) was falling quickly because of isostatic rebound. We use the background rate of RSL fall, together with an age model for the sediment sequence, to infer a minimum wave run-up during the event of c. 3.3 m. The stratigraphic signature of the event bears similarities to that described from studies of the early-Holocene Storegga slide tsunami in Norwegian coastal basins. Conditions conducive to iceberg tsunami include a supply of icebergs, deep water close to the shore, a depositional setting protected from storms or landslide tsunami, and a coastal configuration that has the potential to amplify the height of tsunami waves as water depths shallow and the waves approach and impact the coast. Future warming of polar regions will lead to increased calving and iceberg production, at a time when human use of polar coasts will also grow. We predict, therefore, that iceberg-generated tsunami will become a growing hazard in polar coastal waters, especially in areas adjacent to large, fast-flowing, marine-terminating ice streams that are close to human populations or infrastructure.
Description
Sponsor
Polish National Science Centre grant No. 2011/01/B/ST10/01553; NERC ARCICE thematic programme (GST022189); NERC Radiocarbon Dating Allocation No. 836.1299.
Keywords
Iceberg, tsunami, isolation basin, coastal lake, relative sea level, natural hazard, Greenland, Arctic, lake sediments, tsunami deposits, diatoms, geohazards
Citation
Arktos vol. 1: 6, 2015, 16 pages