| MMS ENVIRONMENTAL STUDIES PROGRAM: ONGOING STUDIES | ||||||
| MMS OCS Region: | Pacific | |||||
| Title: | Santa Maria Basin/Santa Barbara Channel Natural Tar Seep Mapping (PC-01-04) | |||||
| Total Cost: | $407,749,000 | Period of Performance: | FY 2001-2006 | |||
| Conducting Organization: | U.S. Geological Survey - Menlo Park, CA | |||||
| MMS Contact: | Mary Elaine Helix | |||||
| Description: | ||||||
| Background | ||||||
| Numerous active natural tar seeps
in the area of active Pacific OCS operations release oil into the ocean
every day. Some seeps are reported to release upwards of 100 barrels per
day. The best source of information documenting and mapping their presence
in the Santa Barbara Channel is a report which documents the presence of
over 2,000 seeps in State waters in the Santa Barbara Channel alone (State
Lands Commission, 1978). There are no other comparable data for the Santa Maria Basin and no study in the past 20 years in the Santa Barbara Channel. This type of information is needed to assess possible effects from OCS oil spills. The Platform Irene-to-shore pipeline spill occurred in an area where, based on MINT data, oil seeps are very active and the oil issuing from the seeps often lands on the shoreline. But MMS lacks the information to document how much this natural seepage contributes to the ocean waters. This has been problematic when oil spills from OCS facilities have occurred, for example, during the Torch Platform Irene pipeline spill. Though spill responders and biologists found oil on the shoreline following the spill, it was difficult to determine if its source was Platform Irene, or was from natural seeps. It is believed that a large percentage of the coastline where oil was identified and asserted to be Torch’s may actually be from natural seepage or other unknown spills. Impacts on the biota are also not easy to assess because we do not know the normal exposure level in the area. Information about the natural seep volume released in the area, its most likely depositional areas, and exact identification (fingerprinting) are needed to adequately address this problem. There is insufficient data in the Santa Maria Basin to estimate either the number of seeps, their location or the quantity of seepage. Data in the Channel is sufficiently old to be of questionable value. |
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| Objectives | ||||||
| To determine the location, volume, and chemistry of natural tar seeps in the Santa Maria Basin and western Santa Barbara Channel. | ||||||
| Methods | ||||||
| There are three specific tasks: identification,
sampling, analysis. Identification: We are currently examining geohazard records, biological survey data, and aerial photography records to determine potential seep locations. Inhouse expertise of physical oceanography would also be used to trace potential seep origin based on knowledge of shoreline tar deposition. From this first effort, four or five areas will be targeted for further research. It is expected this component will be completed by Fall 2000. Sampling: Second, an ROV would be used to sample pre-planned transects in each of the targeted areas to quantify the number and activity of tar seeps. Samples of tar would also be collected. Tarballs would also be collected at key depositional locations along the shoreline for analysis. Selected samples of oil from offshore platforms would also be collected as appropriate. Analysis: Collected samples of tar and tarballs would be analyzed and fingerprinted by geologists and geochemists at the USGS. Volumes of gas and oil would be quantified. Shoreline deposits would be mapped in relation to their seep origin. |
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| Importance to MMS | ||||||
| The information is needed to assess natural seepage so that OCS operations can be placed in context with the natural environment. This is especially true in regard to MMS's responsibility to assess the risk of oil spills in the marine environment compared to the effects of other sources of hydrocarbons. MMS needs to be able to determine the direct impact from OCS oil and gas operations, and be able to conclusively determine that oiled areas along the shoreline are or are not from these operations. | ||||||
| Current Status: | ||||||
| Work has been completed, analysis completed and draft report expected early December. | ||||||
| Final Report Due: | 12/29/2006 | |||||
| Publications: | ||||||
| Affiliated WWW Sites: | http://www.mms.gov/omm/pacific/enviro/submarine-oil-seep-study/submarine-seeps.htm | |||||
| Revised date: | November 29, 2006 | |||||
| ESPIS |
ESPIS - All completed
ESP Studies: |
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