Pulling the rug out from under California: Seismic images of the Mendocino Triple Junction region

Anne M. Trehu

doi:10.1029/95eo00229

Home/Archive/USGS

USGS · 70133685

Pulling the rug out from under California: Seismic images of the Mendocino Triple Junction region

Anne M. Trehu

View original source ↗Export metadata ↓

Abstract

The active tectonic regime of northwestern California changes abruptly from transform motion to subduction at the Mendocino Triple Junction. Northward migration of the triple junction has been a major factor in the tectonic history of the continental margin of California since the Oligocene and continues at present. Understanding the effects of triple junction migration on the structure of the crust and upper mantle in this region is therefore necessary for reconstructing the geologic evolution of the continental margin of California and accurately assessing seismic hazards associated with the San Andreas fault system and the Cascadia subduction zone. In 1993 and 1994 a network of large-aperture seismic profiles was collected to image the crustal and upper-mantle structure beneath northern California and the adjacent continental margin. The data include approximately 650 km of onshore seismic refraction/reflection data, 2000 km of off-shore multichannel seismic (MCS) reflection data, and simultaneous onshore and offshore recording of the MCS airgun source to yield large-aperture data. Scientists from more than 12 institutions were involved in data acquisition.

Explore related subjects

Eos, Transactions, American Geophysical Union Article

Source-reported bounding extent: 39° to 41° latitude; -125° to -123° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Anne M. Trehu. 2006-10-19. Pulling the rug out from under California: Seismic images of the Mendocino Triple Junction region. https://doi.org/10.1029/95eo00229

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2019

Better approaches to managing drought in the American Southwest

The second in a series of USGS Southwest Region (SWR) “Science Exchange” annual workshops, focused on USGS drought science. The participants considered how extreme drought conditions are evolving in much of the American southwest, with an emphasis on integrated drought science planning at the USGS bureau and program levels. The increased need for interdisciplinary science to support resource-management decisions systems, was highlighted. The workshop brought together scientists and program managers from USGS with Bureau of Land Management, National Oceanic and Atmospheric Administration, US Bureau of Reclamation and state water management departments. Key objectives of the workshop were to improve awareness of ongoing drought-science work within the region, highlight the capabilities of USGS-SWR science centers in drought science, and build new relationships to advance best approaches in drought science. Topics covered in presentations and demonstrations were broad-ranging and included monitoring for drought early warning; water use and water production associated with petroleum production; paleo perspectives on drought, and ecological consequences of drought to native fish.

Eos, Transactions, American Geophysical Union↗

USGS2017

Defining opportunities for collaboration across data life cycles

Monitoring natural resources - water, forests, and animal populations—is required to support effective management of natural resources. However, because monitoring activities are often specific to a discipline, issue, or agency, it is typically difficult to integrate data to answer questions that transcend geopolitical and jurisdictional boundaries. How do we reach the better data integration we need?

Eos, Transactions, American Geophysical Union↗

USGS2014

Coastal fog, climate change, and the environment

Coastal marine fog, a characteristic feature of climates generated at the eastern boundaries of ocean basins worldwide, evokes different feelings in those who experience it (see Figure 1). Authors and poets use fog to represent mystery, bleakness, and confusion. Film directors seek out fog to shroud scenes in eerie gloominess. Tourists visiting beaches bemoan the cool and damp conditions that create a striking contrast to the sunny warm conditions typically found less than a few kilometers inland. Airline passengers delayed by fog impatiently wait for the skies to clear. Residents get used to the Sun “rising” in midday after fog dissipates.

Eos, Transactions, American Geophysical Union↗