• Multichannel seismic velocity...

Treffer: Multichannel seismic velocity analysis of southern Cascadia Margin using seismic traveltime tomography

Title:
Multichannel seismic velocity analysis of southern Cascadia Margin using seismic traveltime tomography
Authors:
Carlus, Richel
Publisher Information:
Texas A&M University-Kingsville
Publication Year:
2022
Collection:
Texas A&M University-Kingsville: AKM Digital Repository
Subject Terms:
Petrophysics, Hydrate Ridge, Seismology -- Data processing, Seismic waves, Geophysics -- Data processing
Document Type:
other/unknown material
File Description:
pdf; 3,726,946 bytes
Language:
English
Relation:
http://cdm16771.contentdm.oclc.org/u?/p16771coll2,1188
Availability:
http://cdm16771.contentdm.oclc.org/u?/p16771coll2,1188
Rights:
The right to download or print any of the pages of this thesis (Material) is granted by the copyright owner only for personal or classroom use. The author retains all proprietary rights, including copyright ownership. Any reproduction or editing or other use of this Material by any means requires the express written permission of the copyright owner. Except as provided above, or any use beyond what is allowed by fair use (Title 17 Section 107 U.S.C.), you may not reproduce, republish, post, transmit or distribute any Material from this web site in any physical or digital form without the permission of the copyright owner of the Material. Inquiries regarding any further use of these materials should be addressed to Administration, Jernigan Library, Texas A&M University-Kingsville, 700 University Blvd. Kingsville, Texas 78363-8202, (361)593-3416.
Accession Number:
edsbas.94FED2EB
Database:
BASE

Weitere Informationen

The sedimentation and tectonic history of the Cascadia Margin is complex and poorly understood. Using multichannel seismic data from margin-perpendicular Line 6 collected by the U.S Geological Survey (USGS) off Cape Blanco, Oregon, in 1994, we obtained a better image of seismic structures and accretionary wedge sediments. Our results will help understand local deformation within the Cascadia basin and accreted wedge sediments. Seismic data processing up to migration revealed prominent sedimentary structures. Multiple slope failure deposits were observed in the Cascadia basin sediments, which could be traced back to a large slope failure feature observed 8 km landward of the deformation front. A discontinuous bottom simulating reflector (BSR) is observed in the accreted sediments, and is absent beneath the slope failure feature. Furthermore, a large seafloor scarp of ~150 m is observed within the slope failure region, and appears to coincide with a deep-seated fault that potentially acts like a gas migrating conduit. These results suggest a link between the slope failure events observed in this region and the presence of gas hydrates. Furthermore, traveltime inversion was performed on the landward portion of Line 6 to obtain tomographic velocities. The final tomographic velocity model resolves structures down to 1 km below the seafloor, and compares reasonably well with the nearby sonic velocities. This project highlights the need for higher resolution imagery to be able to detect evidences of the interplay of gas hydrates and sediment along a complex margin.