Researchers at UCSB recently discovered a submerged island off the Santa Barbara coast, which has been named Isla Calafia after a mythical queen who once ruled a Utopian island of beautiful, warrior women.
Geology Professor Edward Keller and his team made the discovery last year while researching the earthquake hazard in Santa Barbara. After a decade of study the team decided to look at geological folds within the channel a couple of years ago and found the island, Keller said.
Isla Calafia is submerged under 300 feet of water and lies halfway between Santa Cruz Island and the Santa Barbara coast. It was last above water 15,000 to 18,000 years ago. Folding is a process in which continental plates grind across one another, compressing the ocean floor and causing it to fold. The island itself is an upward-bulging fold called an anticline.
“We’ve always known [islands] were there, we just didn’t have good enough topographic data,” Keller said. “I was probably one of the first people to look at details of the topographic data of that part of the channel.”
The island is rising at the rate of six feet per1,000 years, which means it will not resurface for another one million years unless there is a period of glaciating – a span of time when glaciers form and cause the sea level to lower. For the past 18,000 years, two faults have shaped the anticline and the consequent thickening in the earth’s crust has kept the island in the same position, he said.
Keller believes when the sea level was lower and Isla Calafia was still above water – about 50,000 to 60,000 years ago – Columbian mammoths were able to swim to the island.
Methane seeps have also been found on Isla Calafia, though not on the ocean basin around it, according to Keller.
“The methane is something that you normally expect in an oil field,” he said. “This structure out there … is an oil field. Methane forms along with oil. When it gets trapped near the surface, we’re wondering if occasionally the methane would be released.”
The methane was discovered a year ago, but a recent radiocarbon date shows that the sediment around the methane seeps is approximately 11,000 years old.
“Eleven[thousand years] is geologically a blink of the eye,” he said
Keller will speak tonight at 7 in the Maritime Museum at the Santa Barbara Harbor. Geology Professor Jim Kennett, Institute for Crustal Studies research assistant Marc Kamerling, Ph.D student Tessa Hill, and Peter Eichhubl of the Monterey Bay Marine Lab, all co- authored the research.