North America’s largest recorded earthquakes and largest documented volcanic eruptions both take place in southwest Alaska. A major shoreline-crossing community seismic experiment commenced in 2018, focused on the Alaska Peninsula subduction zone. Alaska is a GeoPRISMS primary site and current EarthScope target. The deployment is augmented by deployment of EarthScope Transportable Array (TA) seismic stations, earthquake and volcanic monitoring networks, and the recent development of a large pool of ocean bottom seismographs (OBSs). Together, these resource provide a unique opportunity to advance understanding of Alaska and subduction processes generally.
AACSE collects seismic data remotely onshore and offshore, all of which will be freely released to the community as rapidly as possible. The array includes 75 broadband OBSs and 30 land broadband sensors, recording for 15 months beginning May-June 2018. The array covers a broad area that spans the incoming plate, the megathrust and volcanic arc to the distal backarc, and includes a dense transect in the Kodiak/Katmai region. When integrated with the TA, the array extends 1500 km from incoming plate to the Arctic coast and spans 700 km along strike. The OBSs include 20 shielded sensors for deployment in shallow water. Many OBSs include absolute pressure gauges to capture possible slow slip events, while five OBSs and six land sites will include accelerometers to record large local earthquakes without clipping.
The AACSE broadband OBS deployment completed on July 20, teams of scientists deployed 75 instruments across two sailing legs aboard the R/V Sikuliaq. Twelve Apply-to-Sail participants and two K-12 teachers from Alaska participated in the deployment cruises by performing watchstanding duties, helping prepare instruments for deployment and maintaining the project blog.
The Sikuliaq runs multiple acoustic and oceanographic sensing systems while underway including: ocean current measurements (ADCP), seawater temperature, conductivity and density (CTD), echo sounder for fisheries research (EK60), multibeam bathymetry (32kHz Kongsberg EM302), parametric sub-bottom profiler for shallow subsurface imaging (Kongsberg TOPAS PS 18), R2R event logger, expendable bathythermograph for measuring water temperature (XBT). All data will be archived and available via the UNOLS R2R server. Additionally, multibeam data will be archived via the MGDS and sub-bottom data will be archived at the UTIG Academic Seismic Portal. For access to the data prior to archiving, contact the cruise co-chief scientists: Leg 1 – Lindsay Worthington (lworthington (at) unm.edu) and Leg 2 -Anne Sheehan (anne.sheehan (at) colorado.edu). Cruise reports available here: link to cruise report
The onshore broadband seismometers were deployed May-June 2018, with 29 stations installed on Kodiak, the Shumagin Islands, and the Alaska Peninsula. All stations include Nanometrics posthole PHQ-120 sensors recorded on Quanterra Q330 data loggers placed in low-profile aluminum boxes; the blog shows some photographs of installations. Six of those sites also record Titan accelerometers, all at 100 sps. The first onshore data were recovered during a service run in August-September 2018, and are NOW AVAILABLE at the IRIS DMC, network code XO. OBS data will be available after recovery in 2019.
A map of the current deployment plan and a detailed deployment plan can be found on the links below. The project is intended to help grow the seismological community, and includes opportunities to sail on OBS cruises and short courses for undergraduates – 2019 opportunities to be announced in December 2018! Feel free to contact members of the PI team for more information.
Alaska Amphibious Community Seismic Experiment (AACSE)
icon-chevron-right Download the Deployment map (PDF, last update September 18, 2018)
Preliminary station locations
These locations are based on initial surveys only, and will be superseded by metadata generated when data are submitted to the IRIS DMC. They are provided for reference. Please use the metadata at the DMC for all analyses, once it is available. List of land stations, and of OBSs.
- All earthquake seismic data will be made available as it is retrieved and archived, through the IRIS DMC – OBS array has network code XD (2018-2019) and land array has network code XO (2018-2019).
- Underway marine data including multibeam bathymetry are being made available through MGDS and embedded into the GMRT grids, available through GeoMapApp and other interfaces. The deployment cruises are SKQ201811S and SKQ201816S.
- Sub-bottom TOPAS profiler data was collected on the Sikuliaq during both 2018 deployment cruises, and are being made available through the Academic Seismic Portal at UTIG.
icon-link Project web page: http://geoprisms.org/research/community-projects/alaska/
icon-chevron-right First land data now available! All data are at the IRIS DMC, network code XO for land data and XD for OBS data
AACSE is deployed! The land array was deployed May-June 2018, and the OBSs finished deployment on July 20 2018
The AACSE deployment has been funded and is scheduled for spring, 2018 deployment!
The AACSE plan will be presented and discussed at the September 2017 OBS Workshop in Portland, Maine!
The AACSE project team convened a GeoPRISMS MiniWorkshop just prior to the 2017 AGU in New Orleans
A webinar (April 25, 2016) introduced the community to the exciting scientific opportunities that this DCL offers and to outline general strategies for achieving them. Watch the record of the webinar below.
Presenters: Susan Schwartz, Geoff Abers, Emily Roland, Rob Evans, Doug Wiens, Jeff Freymueller
Apply to Sail with the Alaska Amphibious Community Seismic Experiment.
Application Deadline is now passed
Cruise Dates (+/- 5 days; arrive 2 days before departure date):
- Leg 1: June 6 – June 24, 2019 (R/V Marcus G. Langseth: active source seismic survey)
- Leg 2: Aug 10 – Aug 29, 2019 (R/V Sikuliaq: passive OBS recovery)
- Leg 3: Aug 27 – Sep 12, 2019 (R/V Marcus G. Langseth: passive OBS recovery)
Graduate students and scientists at all career stages are invited to sail with the Alaska Amphibious Community Seismic Experiment (AACSE) aboard one active source seismic cruise during late Spring 2019, and two OBS recovery legs during the late summer and early fall of 2019. The AACSE is major shoreline-crossing community experiment focusing on the subduction zone offshore the Alaska Peninsula, which has been the site of North America’s largest recorded earthquakes as well as major volcanic hazards. Data are collected during the 15-month experiment using 75 broadband ocean bottom seismometers (OBS) and 30 land stations.
- OBSs will be recovered by two legs in August aboard the Global-Class R/V Sikuliaq and in September aboard the R/V Langseth. Participants will be involved with all aspects of the scientific process by assisting in OBS recoveries and with multibeam bathymetry data, documentation of the expedition, preparation of cruise reports, and documenting the cruise via social media.
- An active source seismic cruise will be conducted aboard the R/V Langseth in June. This cruise will include an educational component for those interested in learning about marine active source imaging methods. Duties of participants on this cruise will include keeping acquisition logs, acquiring multibeam bathymetry and 3.5 KHz data, documentation of the expedition, preparation of cruise reports, and documenting the cruise via social media.
The PI team anticipates that berths for 4 to 6 additional students or scientists will be available on each leg. The cruises will be aboard working vessels with 24-hours operations, and participants will be unable to return to shore during the expedition. Participants should anticipate difficult conditions including rough seas, long hours, close quarters, constant noise, foul odors, and limited medical facilities. Travel costs to and from the departure and arrival ports, meals, and lodging will be paid for Apply to Sail participants, but no stipend is included.
To apply to sail with the AACSE cruise, each applicant should submit a 2-page CV, a brief statement of interest, and a statement of relevant experience. Applicants who will be graduate students during the summer/fall of 2019 should also submit a letter of support from their graduate advisor. Applications are now closed. Please direct any questions about the Apply to Sail application process to Aubreya Adams (aadams (at) colgate.edu). Questions specific to the passive source cruises should be directed to Aubreya Adams, and questions regarding the active source cruise should be directed to Anne Becel (annebcl (at) ldeo.columbia.edu).
Applications are now closed
The Alaska Amphibious Community Seismic Experiment (AACSE) Team is pleased to invite applications from undergraduate students to join a short course on the Tectonics and Seismicity of the Alaskan Subduction Zone. The short course will be based in Kodiak, Alaska June 14-23 (±2 days) and will include a three-day workshop followed by field work with seismic instrumentation.
During the workshop, participants will learn earthquake science and tectonics, will be introduced to seismic theory and data, and will explore the earthquake geology of the Kodiak region. Following the workshop, students will join in the recovery of a 400 station nodal array across Kodiak with members of the science team.
Applicants should anticipate that this short course will require a 24/7 commitment during the course, will involve work early in the morning and late at night, and require shared accommodation. This no-credit short-course is tuition free, and transportation, room and board will be provided for approximately six students selected to attend the short course, but no stipend is included.
Applications from current sophomores, juniors, and seniors pursuing a degree in geoscience, physics, computer science, applied mathematics, engineering or related majors at a US institution are encouraged.
Applicants should submit the following information by April 1:
- No more than 2-page resume
- No more than 1-page Statement of Interest
- List of relevant classes
- Name and email address for one professional reference. Applicants should ask the reference writer to submit a letter of reference via email to aadams (at) colgate.edu by April 1.
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