Two years ago,  we posted about Saildrone‘s new 72’ long Surveyor, which was described as the world’s most advanced uncrewed surface vehicle (USV), equipped for high-resolution mapping of the ocean seafloor.

Now, the Saildrone Surveyor has discovered a 3,300-foot-tall sea mountain, or seamount, about 200 miles off the coast of California.

The Los Angeles Times reports that starting last summer, the Saildrone Surveyor spent several months exploring the Aleutian Islands in Alaska and the ocean off California in an expedition funded by the National Oceanic and Atmospheric Administration (NOAA) and the Bureau of Ocean Energy Management.

The vehicle mapped more than 13,000 square nautical miles during its expedition.

“When [the seamount] was found, people got really excited that there was a big feature that no one was previously aware of and that had not yet been mapped in any kind of detail,” said Aurora Elmore, cooperative institute manager at NOAA, in an interview with The Times.

The discovery was notable for a couple of reasons, Elmore explained — the seamount was found in an area where the features are uncommon, and it has an unusual shape.

“There are other seamounts along the coast of California,” she said, “none in this exact region, but some to the north and to the south.”|
 
Additionally, seamounts are commonly shaped like mountains on land, with sloped sides leading to a peak. But the one discovered by Saildrone more closely resembles a butte like those found in the deserts of the Southwest.

Its sides are sheer and vertical, and on its top is a 100-foot-deep caldera.

Elmore said researchers do not know why or how the seamount gained its cylindrical shape but said it was most likely a volcanic formation.

The Surveyor carries a sophisticated array of acoustic instruments for both shallow and deep-water ocean mapping; the Kongsberg EM 304 multibeam echo sounder is capable of mapping the seafloor down to 7,000 meters below the surface. The Surveyor also carries two state-of-the-art Acoustic Doppler Current Profilers (ADCPs), the Teledyne Pinnacle 45 kHz ADCP and the Simrad EC150-3C ADCP, to measure ocean currents and understand what is in the water column. The Surveyor is also equipped with the Simrad EK80 echo sounder for fish stock assessments.