Cascadia

PIs:

The Cascadia Initiative is a community seismic experiment. Cascadia Cruises are led by the Cascadia Initiative Epedition Team (CIET), comprised of the following team of scientists:

Doug Toomey, Team Leader, University of Oregon
Richard Allen, University of California, Berkeley
John Collins, Woods Hole Oceanographic Institution
Bob Dziak, OSU/NOAA, Newport, OR
Emilie Hooft, University of Oregon
Dean Livelybrooks, University of Oregon
Jeff McGuire, Woods Hole Oceanographic Institution
Susan Schwartz, University of California, Santa Cruz
Maya Tolstoy, Lamont Doherty Earth Observatory
Anne Trehu, Oregon State University
William Wilcock, University of Washington.

Experiment Summary

The Cascadia Intitiative is an onshore/offshore seismic and geodetic experiment deployed in the Pacific Northwest to study questions ranging from megathrust earthquakes to volcanic arc structure to the formation, deformation and hydration of the Juan De Fuca and Gorda plates.

As part of the 2009 Stimulus or ARRA (American Recovery and Reinvestment Act) spending, NSF’s Ocean Sciences (OCE) division funded the construction of an amphibious array of 60 Ocean Bottom Seismometers by the three IIC’s for OBSIP.

Cascadia Amphibious Array Design

Twenty of the Lamont OBSs will be installed in trawl-resis- tant enclosures and will be available for deployments in water depths extending from the shelf down to 1,000 m. These 20 OBSs will be deployed via the ship’s wire and recovered using a Remotely-Operated Vehicle.

The OBSs will be utilized in four one-year deployments. These experiments will provide an offshore extension of the Earth- Scope Transportable Array (~70 km spacing) as well as 3 dense experiments focused on either imaging various properties of the thrust interface and forearc or recording local seismicity.

Experiment Website

Articles

Science Advances 24 May 2017 "High seismic attenuation at a mid-ocean ridge reveals the distribution of deep melt" Z. C. Eilon, and G. A. Abers.

The UC Santa Barbara Current 24 May 2017 "The Birth and Death of a Tectonic Plate" J. Cohen.

Science 23 September 2016 "Tomography reveals buoyant asthenosphere accumulating beneath the Juan de Fuca plate" W. B. Hawley, R. M. Allen, and M. A. Richards.

Berkeley News 22 September 2016 "Seismic ‘CT scans’ reveal deep earth dynamics" W. Ravven.

Cruises

During 2015, OBSIP supported the following Cascadia cruises:

Cascadia 5A, RV Oceanus, Recover 15 WHOI OBS instruments - August/September
Cascadia 5B, RV Oceanus, Recover 15 SIO OBS instruments - September
Cascadia 5C, RV Atlantis, Recover 29 LDEO OBS instruments - September/October

During 2014, OBSIP supported the following Cascadia cruises:

Cascadia 4A, RV Oceanus, Recover 25 WHOI OBS instruments - June
Cascadia 4B, RV Oceanus, Recover 15 SIO OBS instruments - June
Cascadia 4C, RV Atlantis, Recover 30 LDEO OBS instruments - June/July
Cascadia 4D, RV Oceanus, Deploy 25 WHOI OBS instruments - August
Cascadia 4E, RV Oceanus, Deploy 15 SIO OBS instruments - August
Cascadia 4F, RV Oceanus, Deply 30 LDEO OBS instruments - August/September

During 2013, OBSIP supported the following Cascadia cruises:

Cascadia 3A, RV Oceanus, Recover 25 WHOI OBS instruments - June
Cascadia 3B, RV Oceanus, Recover 15 SIO OBS instruments - June
Cascadia 3C, RV Atlantis, Recover 30 LDEO OBS instruments - June/July
Cascadia 3D, RV Oceanus, Deploy 25 WHOI OBS instruments - August
Cascadia 3E, RV Oceanus, Deploy 15 SIO OBS instruments - August
Cascadia 3F, RV Oceanus, Deply 30 LDEO OBS instruments - August/September

During 2012, OBSIP supported the following Cascadia cruises:

Cascadia 2A, RV Oceanus, Recover 15 OBS instruments - May
Cascadia 2B, RV Thomas Thompson, Recover 24, Deploy 6 OBS instruments - July
Cascadia 2C, RV New Horizon, Recover 15 OBS instruments - July
Cascadia 2D, RV Oceanus, Deploy 15 OBS instruments - August
Cascadia 2E, RV Oceanus, Deploy 15 OBS instruments - August/September
Cascadia 2F, RV Oceanus, Deply 24 OBS instruments - September
Cascadia 2G, RV Oceanus, Contingency Cruise - November

Data

Data from the ocean bottom seismometers will be archived at the IRIS DMC under temporary network code 7D (four years of OBSIP deployments) and 7A (first deployment of WHOI-Keck). Temporary and permanent broadband land stations are archived under the network codes 5E (PASSCAL 2014-2015), BK (Berkeley Digital Seismograph Network), IU (Global Seismograph Network), TA (EarthScope Transportable Array), UO (University of Oregon Regional Network), US (US National Seismic Network), and UW (Pacific Northwest Regional Seismic Network). All stations will be available using the virtual network _CASCADIA.