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Gofar TF Earthquakes
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2021
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Global
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Project Title: |
Capturing 4D Variations in Stress, Slip, and Material Properties: The 2019-2021 Gofar Transform Fault Earthquake Prediction Experiment |
Project Status: |
Submitted |
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Principal Investigator: |
Margaret Boettcher, UNH |
Project Institution: |
UNH |
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Project ID: |
106088 |
Version #: |
16 |
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Date Submitted: |
2/13/2018 2:25:00 AM |
Created By: |
Margaret Boettcher |
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Date Last Modified: |
7/30/2021 5:52:00 AM |
URI Serial #: |
None |
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Funding Agencies: |
NSF/OCE/MGG - 1832830 - Funded |
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Summary of Field Work: |
Field work will be focused on a 2 year ocean bottom seismometer (OBS) experiment on a transform fault that we know is nearing the end of its seismic cycle. We will deploy 23 strong motion or broadband OBSs and 28 short period OBSs to record earthquakes in the expected range of 0 < Mw < 6.2 in two back-to-back 1-year deployments. These observations will be used to investigate the mechanics of fault slip and earthquake physics. We will also map regions around the fault zone to link earthquake cycles to seafloor geology, fluid flow, and magnetics. This work will be accomplished during a set of three cruises, which include:
Cruise 1- (i) OBS deployments, including 23 strong motion/broadband and 28 short period instruments and (ii) rock dredging on Gofar TF and nearby Quebrada TF;
Cruise 2- (i) Recover and redeploy OBSs
Cruise 3- (i) Recover OBSs; (ii) deploy AUV Sentry for 13 dives to survey the seafloor and collect chemical sensor data; and (iii) Electromagnetic Surveys from a separately funded grant to Rob Evans (WHOI) |
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Summary of Facility Requirements: |
Our facility requirements include coordinating with OBSIP to obtain 28 short period OBS instruments and 23 strong ground motion and/or broadband OBS instruments. To support the deployment and recovery of the OBSs we will need a Hydro Winch, Dynamic Positioning, two vans, and we will have hazardous materials. We will need USBL beacon tracking ability to deploy the short period OBSs via wireline to enable ~10m position precision.
In addition, for the first cruise we will require the ability to rock dredge with a wire and winch for 3000-5000m depth, and for the third cruise we will need AUV Sentry and a CTD/rosette. |
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Summary of other requirements and comments: |
The timing of this project is tightly constrained by the expected occurrence times of two magnitude 6 earthquakes on the Gofar TF. To maximize our chances of success at capturing these events, we need the first cruise to happen in the late spring – summer of 2019 [this occurred in Nov/Dec 2019]. The second cruise would need to be approximately 12 months after the first one, to allow us to recover OBSs and replace batteries without any data gaps. The third cruise would need to be 12-16 months after the second cruise. These timing constraints will allow us to have continuous recording of the seismicity during the peak of the expected recurrence interval for the large earthquakes in our study area. |
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Type of Request: |
Primary Ship Use |
Request Status: |
Submitted |
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Request ID: |
1009842 |
Created By: |
Margaret Boettcher |
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Date Last Modified: |
7/30/2021 5:52:00 AM |
Date Submitted: |
2/13/2018 2:25:00 AM |
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Year: |
2021
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Ship/Facility: |
Global
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Optimum Start Date:
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1/15/2021 |
Dates to Avoid: |
This cruise needs to be no later than mid-January to allow us to recover the OBSs before their batteries die at the end of Jan. 2021. |
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Earliest Start Date: |
10/15/2020 |
Multi-Ship Op: |
No |
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Latest Start Date: |
1/15/2021 |
Other Ship(s): |
N/A |
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Operating Days Needed: |
Science Days |
Mob Days |
De-Mob Days |
Estimated Transit Days |
Total Days |
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20 |
2 |
2 |
18 |
42 |
Repeating Cruise?
(within same year) |
No |
Interval: |
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# of Cruises: |
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Description of Repeating cruise requirements: |
N/A |
Justification/Explanation for ship choice, dates,
conflicts, number of days & multi-ship operations: |
N/A |
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Short Description of Op Area
for use in schedules: |
Gofar TF, EPR |
| Description of Op Area: |
Gofar Transform Fault, East Pacific Rise |
| Op Area Size/Dia.: |
44 |
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Lat/Long |
Marsden Grid |
Navy Op Area |
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Beginning
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4° 42' S
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106° 12' W
map
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Ending
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4° 30' S
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105° 30' W
map
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Show Degrees Minutes |
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Foreign Clearance Required? |
No |
Coastal States:
NONE |
 Important Info on Foreign Research Clearances
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Are you or any member in your science party bringing in any science equipment items which are regulated for export by the International Traffic in Arms Regulations (ITAR) and/or the Export Administration Regulations (EAR)?
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No |
If yes, have you applied for the necessary permits through your export control office?
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No |
| Questions about ITAR/EAR regulations?
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Comments about foreign clearance requirements or
description of any other special permitting requirements
(e.g., MMPA, ESA, IHA, Marine Sanctuaries, etc.) |
N/A |
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Requested Start Port |
Intermediate Port(s) |
Requested End Port |
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San Diego, CA, USA |
None, |
San Diego, CA, USA |
Explanation/justification for requested
ports and dates of intermediate stops
or to list additional port stops |
San Diego is the closest US port to Gofar TF. |
Important Info on Working in Foreign Ports
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Chief Scientist: |
John A. Collins, WHOI |
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# in Science Party |
6 |
# of different science teams |
2 |
# Marine Technicians to be
provided by ship operator:
(include in science party total)
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2 |
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Explanation of Science Party Requirements and Technician Requirements |
The science party will include scientists (1) and an OBSIP team (5). We will be recovering and redeploying 51 OBSs |
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 Dynamic Positioning | ADCP | Multibeam |  Seismic |
| Dredging/Coring/Large Dia. Trawl Wire | Stern A-frame | Fiber Optic (.681) | 0.680 Coax Wire |
| SCUBA Diving | Radioisotope use - briefly describe | NO Radioisotope use/Natural level work | Other Operator Provided Inst. - Describe |
| 3 PI-Provided Vans - briefly describe | MOCNESS | | |
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Explain Instrumentation or Capability
requirements that could affect choice
of ship in scheduling. |
We will be recovering and re-deploying 51 Ocean Bottom Seismometers and will need to coordinate with OBSIP. We will also be conducting an EM experiment. OBSIP will bring 2 vans and the Scripps EM group will have 1 van. Additionally, we require a USBL beacon, a Winch-Pool Winch with heave-compensation, and XBT.
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Explain Major Ancillary Facilities
Requirements and list description
and provider for "other" systems. |
We require coordination with OBSIP. We require a winch-pool winch with heave-compensation, as well as a USBL beacon. |
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