Geological and Sedimentological Evidence of a Large Tsunami Occurring ~1100 Year BP from a Small Coastal Lake along the Bay of La Paz in Baja California Sur, Mexico

Journal of Marine Science and Engineering

Terrence A. McCloskey¹  Thomas A. Bianchette²  Kam-biu Liu²  Valentin Heller² 

[1] Department of Oceanography and Coastal Sciences, School of the Coast and Environment, Louisiana State University, 1002Y Energy Coast and Environment Building, Baton Rouge, LA 70803, USA;

关键词: tsunami;    Baja California;    event deposit;    coastal hazards;   

DOI  :  10.3390/jmse3041544

来源: mdpi

【 摘 要 】

The importance of small-scale seismic events in enclosed water bodies, which can result in large tsunami waves capable of affecting comprehensive damage over small, geographically-confined areas are generally overlooked, although recognizing the occurrence of such events is a necessary element in adequately assessing the risk of natural hazards at specific locations. Here we present evidence for a probable large localized tsunami that occurred within the Bay of La Paz, Baja California Sur, ~1100 year before present (BP), which resulted in the creation of a shelly ridge at an elevation of ~2 m above mean high water (MHW). This ridge consists of a continuous wedge of poorly mixed marine sands and shells ~50 cm in depth deposited along the entire seaward edge of the lake. The marine shells collected from terrestrial environments around the lake include species from a variety of environments, including offshore species with minimum preferred depths of >13 m. The evidence suggests that this material was likely deposited by a tsunami with a runup of 2–3.6 m above MHW, probably associated with the slumping of an island along the tectonically active eastern edge of the bay.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.