Recent Projects
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3D SEISMIC SOLUTIONS – Urban 3D Seismic
U.S. Naval Weapons Station
Seal Beach, California
Project
Perform 3D seismic analysis to identify fault lines and movement for highly sensitive, classified U.S. military installation housing weapons and munitions that re-arm the U.S. Pacific Fleet.
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Challenge
Services must be performed without compromising sensitive installations, damaging surface facilities, or impacting underground infrastructure.
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Results
As part of a larger survey, 3D Seismic Solutions was permitted to extend our survey over a portion of the base so the Navy could further evaluate its impacts and results.
3D Seismic Solutions performed and delivered comprehensive seismic analyses that met/exceeded all conditions specified by the U.S. Navy including no damage to surface facilities and underground infrastructure throughout the process.
3D SEISMIC SOLUTIONS – Fault & Structure Mapping
Cities of Long Beach & Seal Beach, California
Project
Perform 28-square mile 3D survey over portions of Long Beach and Seal Beach to identify faults and possible subsidence.
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Challenges
1. Permitting – getting into the city of Long Beach with seismic trucks and working with the California Coastal Commission for offshore access.
2. Technical – conduct accurate survey in noisy, urban environment, filtering out extraneous noise – including traffic, construction, waves hitting beach – to obtain reasonable, accurate data.
Results
Through instilling confidence in our capabilities with both the city of Long Beach and the California Coastal Commission, our partner, LA Seismic, successfully obtained permits and access, both on land and offshore. 3D Seismic Solutions then performed and delivered comprehensive seismic fault analysis that was shared with Caltech, the California State Geological Survey, and the USGS, for use in determining potential earthquake damage from surface shaking.
Caltech circled back to 3D Seismic Solutions when their analysis provided unexpected results. Subsequent discussions and comparisons of combined datasets provided confirmation of a new interpretation. Reference, click here.
Blind Thrust Faults
Conventional wisdom has assumed a series of strike-slip faults, called the Newport-Inglewood Fault Zone, as the most probable site of the next major earthquake. However, 3D Seismic Solutions’ data shows many different types of faults in the area, including several heretofore unrecognized blind thrust faults.
Blind thrusts, similar to the one that caused the Northridge earthquake, are a particularly dangerous type of fault as they are very difficult to recognize prior to rupture. The seismic section to the left highlights one of the thrust faults that have been identified through our advanced technology.
Surface Intersection
Due to the large amounts of fill (>100 ft as evidenced in well logs) that have been deposited as coastal areas were converted to urban sprawl, any previous surface expression of these faults has been covered. Trenching is unlikely to show any evidence of these buried faults. By examining the seismic data, we can predict where these faults intersect the surface and generate maps to show these locations.
The map to the left depicts where several thrust and normal faults intersect the surface within the area of the 3D survey. Also depicted in translucent red highlighting are areas that have undergone shallow deformation as a result of movement along the newly identified Garden Grove fault.
Subsidence Mapping
Careful, experienced interpretation and analysis has allowed us to quantify some of this recent deformation. We have incorporated this data into a subsidence map illustrated to the left. Areas with the least subsidence are indicated in yellow and areas of maximum subsidence are indicated in red. Contour interval is 100 feet. The amount of subsidence at this horizon is up to 500 feet. The fault surface positions have been overlaid, in purple dashed lines, on the structure map for reference.
Our data, analysis, and mapping shows there was relatively minor subsidence directly under the Seal Beach oil field.