Thermal Structure, hydration and dehydration of the entire Juan de Fuca Plate

Lead PI: James Gaherty, Geoffrey Abers

Unit Affiliation: Seismology, Geology and Tectonophysics, Lamont-Doherty Earth Observatory (LDEO)

August 2013 - July 2017
Inactive
North America ; Juan de Fuca Plate ; Cascadia
Project Type: Research

DESCRIPTION: Seismic data recorded by the Cascadia Initiative array will be analyzed to look at evolution of the ocean lithosphere from ridge to trench on the Juan de Fuca plate. The determined structure will be related to along-strike variation in down-going plate properties (apparent hydration and whether it occurs in the young and/or older plate, thermal structure, segmentation) and seismic behavior along Cascadia subduction zone. Shear wave structure will be determined from surface waves and ambient noise analysis; receiver functions will indicate the depth distribution of interfaces between contrasting properties. Surface wave results will provide the starting model for the receiver function analysis, which will also use results from the COAST study that documented crustal velocity. A graduate student will receive training in seismic analysis and Cascadia processes. A portion of the results will provide context for hazard assessment of the margin, in particular along-strike variability. In-depth use of the CI community experiment data will take place and the results of this study is expected underpin a variety of subsequent geoscience investigations.

SPONSOR:

National Science Foundation (NSF)

FUNDED AMOUNT:

$210,461

WEBSITE:

https://www.nsf.gov/awardsearch/showAward?AWD_ID=1334831&HistoricalAwards=false

PUBLICATIONS:

Janiszewski, H.A. and G.A. Abers. "Imaging the plate interface in the Cascadia seismogenic zone: New constraints from offshore receiver functions," Seism. Res. Lett., v.86, 2015, p. 1261-1269. doi:10.1785/0220150104

KEYWORDS

ambient noise analysis cascadia subduction zone shear wave structure ocean lithosphere