Cascadea subduction1/2/2023 ![]() ![]() The rate of tremor activity near Vancouver Island increased by about 1.5 times from its background level during the passage of seismic waves of this earthquake. The 2012 East Indian Ocean earthquake (M w 8.6), so far the largest intraoceanic plate strike-slip event ever recorded, modulated tectonic tremors in the Cascadia subduction zone. 35 references, 6 = in any discussions of subduction zone earthquakes. Such earthquakes may also be accompanied by large local tsunamis. If large subduction earthquakes occur in the Pacific Northwest, relatively strong shaking can be expected over a large region. Strong ground motions from even larger earthquakes (M/sub w/ up to 9.5) are estimated by simple simulations. My collaborators on this project are Rob McCaffrey at Portland State University and Ken Creager at the University of Washington.This blog covers the talk, and the original slides can be found in my github repo.The paper for which the talk and this blog are based is found here. The nature of strong ground motions recorded during subduction earthquakes of M/sub w/ less than 8.2 is discussed. On April 29, 2014, I presented a talk for Data Rave, NYC at EBay. ![]() If the Cascadia subduction zone is also storing elastic energy, a sequence of several great earthquakes (M/sub w/ 8) or a giant earthquake (M/sub w/ 9) would be necessary to fill this 1200-kilometer gap. Very large subduction earthquakes, ranging in energy magnitude (M/sub w/) between 8 and 9.5, have occurred along these other subduction zones. The Cascadia subduction zone shares many characteristics with subduction zones in southern Chile, southwestern Japan, and Colombia, where comparably young oceanic lithosphere is also subducting. Very young oceanic lithosphere (10 million years old) is being subducted beneath North America at a rate of approximately 4 centimeters per year. ![]() New Juan de Fuca plate is created offshore along the Juan de Fuca Ridge. It separates the Juan de Fuca and North America plates. Large subduction earthquakes on the Cascadia subduction zone pose a potential seismic hazard. The Cascadia Subduction Zone (CSZ) is a 1,000 km (620 mi) long dipping fault that stretches from Northern Vancouver Island to Cape Mendocino in northern California. ![]()
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |