Seabed Mapping Technology and Ocean Management

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Seabed Mapping Technology and Ocean Management
J. Vaughn Barrie
Geological Survey of Canada Pacific School
Earth and Ocean Sciences, University of
Victoria Waterworks Marine Remote Sensing,
October 27, 2004
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Geoscience for Ocean Management
To provide the geoscientific knowledge necessary
for effective decision-making on competing
resource management issues
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ISSUES

• Fisheries
• Oil and Gas
• Wind Farms
• Marine Minerals and Aggregates
• Seafloor infrastructure
• Critical Benthic Habitat
• Marine Protected Areas
• Geohazards

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• Technologies
• Multibeam Swath Bathymetry and Backscatter
• High-resolution sub-bottom profiling
• Sidescan Sonar
• Sediment Sampling (Coring and Grabs)
• Bottom Photography
• Seabed Classification Systems
• Seafloor Magnetics

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Products for Ocean Management Sediment
Distribution Surficial Geology Geohazards Habitat
GIS Integrated Data Base
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Sediment Sampling
Sand
Mud
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Sidescan Sonar
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Sub-bottom Profiling
North Hecate Strait Delta
Cores
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Bottom Photography
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Gas Pipeline
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Surficial Geology Queen Charlotte Basin
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Sockeye E-66
Murrelet L-15
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Multibeam Bathymetry Digital Terrain Images
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Paleo-Lakes
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Search for Life

Concept by Dr. Brian Pratt, U. Sask.
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Geohazards
Fraser Delta Fault
1997 M4.6 1975 M4.9 Earthquakes
Porlier Pass Fault
Earthquakes lt 6 km (1975 -2000) Multibeam
bathymetry with Landsat Imagery for the southern
Strait of Georgia
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Just 1 km northwest of this feature is a second
steep (25o) escarpment oriented at 315o, but with
no identifiable pockmarks.
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• In section, the escarpment can be seen to
  represent the trace of a fault that dips 25o to
  the southwest with over 50 m of apparent throw
  (using 1500 m-s sound velocity).
• On the downthrow side, the seabed is slightly
  domed by 10 m suggesting deformation.

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Porlier Pass Fault
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• The fault is part of an area of highly disturbed
  seafloor with similar faults, some of which break
  Holocene sediments.
• The rolling morphology seen on the multibeam data
  is a result of this zone of deformation.

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Mapleguard Spit - Vancouver Island
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EM-3000 Multibeam
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EM-3000 Backscatter
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Habitat Mapping
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Dixon Entrance
Queen Charlotte Islands
British Columbia Mainland
Hecate Strait
Queen Charlotte Sound
Vancouver Island
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Multibeam image
Reef complexes
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North Hecate Strait Reef Complex
Reefs
5 km
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Reef complexes
Multibeam image
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Multibeam Backscatter Data
Cook Bank
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Summary With the developments in multibeam
mapping technology, in concert with traditional
geoscience survey techniques we now have the
capability to image the seafloor in high
resolution. Integrated Ocean Management
provides a balance for the competing demands of
renewable and non-renewable resources with
conservation through the development of Marine
Protected Areas.
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Questions?