|
Ubiquitous Coastal-Tar Residues on Santa Rosa Island, Offshore Southern California
 |

Locations of tar-residue
samples collected during a joint USGS/NPS field trip in September 2000.

Tar-lined blowhole at Carrington Point.
|
A cooperative field trip with personnel from Coastal and Marine Geology (CMG) and the
National Park Service (NPS) was undertaken in September on Santa Rosa Island, one of
the jewels of the Channel Islands National Park off Southern California. The purpose
was to assess presence of tar residues on all accessible coastlines of the island, collect
floating tar residues on beaches as well as residues fixed to rocky shores near high-tide
lines, fingerprint collected samples geochemically, and determine tar sources. CMG participants
were Tom Lorenson, Keith Kvenvolden, Bob Rosenbauer, and Fran Hostettler (WRC/CMG). NPS
participants were Dan Richards and Sarah Chaney.
Sixty-eight samples of tar residues were collected during the six-day field trip
(see map). Although tar was expected and was found on the north-facing shorelines,
residues were also common on the south-facing shorelines adjacent to the Santa Barbara
channel where natural oil seeps and oil-production platforms are prolific. A most interesting
tar occurrence was found at Carrington Point, the northernmost site on the island, where a
blowhole concentrates floating tar that forms a massive mat on the marine terrace. The
blowhole is lined with tar and is thus protected from rapid erosion by incoming tidal waters
that pass through the pipe-like conduits as geysers (see photo). Preliminary geochemical
analyses indicate several sources for the tar residues, most of which appear to be from
natural oil seeps.
|
 |
Dec. 2000 / Jan. 2001
in this issue:
Santa Rosa Island
cover story: MRIB: Ocean Geo-Library
Nat'l Geography Awareness Week
WHFC GIS Day
Lake Tahoe: "Wonders of the Universe" Calendar
Plymouth County Detention Center
African Dust
Bill Normark Interview
Rock Course for Teachers
Geologic Framework of U.S. Coastal & Marine Regions
Coastal Marsh Die-Back
Southwest Washington Coastal Erosion
Southeatern U.S. Benthic Habitat
Southern California Benthic Habitat
9th International Coral Reef Symposium
Gulf of Maine
Long Island Sound
WHFC at RRT
Distinguished Lecturer
Earthquake Hazards Video
Hapke Honored by CSBPA
Senior Leadership Visit
Director's Office & NOAA Visitors
Suspension Modeling
Dec./Jan. Publications List
 |