Sedimentary evidence for a mid-Holocene iceberg-generated tsunami in a coastal lake, west Greenland

Long, A.J.; Szczucinski, W.; Lawrence, T.

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.

Citation

Long, A., Szczucinski, W., & Lawrence, T. (2015). Sedimentary evidence for a mid-Holocene iceberg-generated tsunami in a coastal lake, west Greenland. Arktos (Cham. Internet), 1(1), Article 6. https://doi.org/10.1007/s41063-015-0007-7

• Journal Article Type: Article
• Acceptance Date: Oct 10, 2015
• Online Publication Date: Nov 20, 2015
• Publication Date: Dec 1, 2015
• Deposit Date: Mar 11, 2016
• Publicly Available Date: Mar 11, 2016
• Journal: arktos
• Print ISSN: 2364-9453
• Electronic ISSN: 2364-9461
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• Volume: 1
• Issue: 1
• Article Number: 6
• DOI: https://doi.org/10.1007/s41063-015-0007-7
• Public URL: https://durham-repository.worktribe.com/output/1409867