With an eye toward giving the State Department the data it needs to expand US borders out beyond the continental shelf, Jim Gardner and researchers at the University of New Hampshire’s Center for Coastal and Ocean Mapping are mapping vast swaths of the sea floor — and revealing a one-of-a-kind glimpse of what lies at the bottom of the ocean. lt;br> The view looking north, toward the Gulf Coast, along a stretch of the continental rise called the http://www.ccom-jhc.unh.edu/unclos/Mexico/obliques/4_bryant_cyn_fan.htm Sigsbee Escarpment — an area where deepwater oil exploration is taking place.
Another view from the http://www.ccom-jhc.unh.edu/unclos/Mexico/obliques/5_keathley_cyn.htm Sigsbee Escarpment; this one shows the topography of an area called Keathley Canyon.
This view, from Gardner’s 2007 Gulf of Mexico cruise, shows an area off the western coast of Florida. The arrows point to a couple of geologic mysteries — so-called http://www.ccom-jhc.unh.edu/unclos/Mexico/obliques/2_plunge_pools.htm plunge pools at the base of the continental shelf. The depressions are not unlike those that might form under water falls on dry land, but Gardner is baffled by what could cause such formations deep underwater.
On a 2006 cruise near Guam and the Northern Mariana Islands, Gardner mapped a dazzling array of coned seamounts. Those pictured here rise off the seafloor along what’s called the http://www.ccom-jhc.unh.edu/unclos/Marianas/obliques/1_Seamounts_of_the_West_Mariana_Ridge.htm West Mariana Ridge.
Gardner’s maps reveal the channels and gouges cut by water moving along the seafloor. This view from the http://www.ccom-jhc.unh.edu/unclos/Marianas/obliques/6_drainage_channels.htm West Mariana Ridge shows the movement of a drainage channel — a sort of underwater riverbed that’s up to 2 kilometers wide.
A view looking east toward the western flank of the http://www.ccom-jhc.unh.edu/unclos/Marianas/obliques/4_western_flank_West_Mariana_Ridge.htm West Mariana Ridge that shows a series of drainage channels running from higher elevation to the smooth seafloor below.
In 2004, Gardner surveyed a vast swath of the Atlantic margin of the eastern seaboard of the US. This image shows http://www.ccom-jhc.unh.edu/unclos/Atlantic/obliques/Atl-oblique_d.htm Knauss Seamount jutting off the seafloor. The dark white line marks the point at which the water is 4,100 meters deep.
From a 2005 trip to the Gulf of Alaska, this view, looking east, shows a series of large formations, including the http://www.ccom-jhc.unh.edu/unclos/Alaska/obliques/S_oblique_2_Horizon.htm Horizon Channel. Draped in the background is the traditional (and far less dramatic) marine chart of the same area.
In 2003, Gardner mapped two portions of the Bering Sea, not far from Alaska’s Aleutian Islands. This view, along a patch of what’s called the http://www.ccom-jhc.unh.edu/unclos/Bering/obliques/bm-oblique_c.htm Beringian Margin, looks east to show the long spurs that extend from the margin.
As geologists — not merely mapmakers — Gardner and the CCOM scientists are constantly trying to understand why the seafloor looks the way it does. Here, an image from the 2005 Bering Sea expedition, shows a large debris avalanche that’s changed the shape of a place called http://www.ccom-jhc.unh.edu/unclos/Bering/obliques/b-oblique_b.htm Bowers Ridge.
