Houston & Texas News
March 11, 2007, 1:22AM
Sub expedition brings back 'promising' clues
By HARVEY RICE
Copyright 2007 Houston Chronicle
GALVESTON — An area discovered on the floor of the Gulf of Mexico about 100 miles south of here could be the remnants of a long-ago shoreline and a place to look for signs of human habitation during the last Ice Age, scientists returning from a submarine expedition said Saturday.
Scientists cautioned that core samples and a more detailed study of the 6-mile-long area are needed before they will know for sure that they are looking at a coastline from 20,000 years ago.
"We found an area that looks like a promising place to do further research," said anthropologist David Robinson, one of 24 scientists on the weeklong expedition in deep water of the Flower Garden Banks National Marine Sanctuary.
The expedition conducted the first underwater search for signs of ancient humans in an area of the Gulf that is now far from shore while gathering biological and geographical information.
The mission also served as a proving ground for new technology that could make undersea exploration more like space exploration.
Scientists beamed information from the Gulf to six control centers in the United States, where scientists directed the expedition in real time.
Robinson and sanctuary Superintendent George Schmahl spent the first three days of the expedition in the belly of the NR-1, a U.S. Navy nuclear research submarine, looking through viewing windows about 18 feet from the sea bottom.
The NR-1 used its sonar to map the ocean floor and sent data to scientists in a control room jammed with scientific equipment aboard the nearby Carolyn Chouest, built to support the NR-1.
From the 238-foot Chouest, scientists deployed the Argus, a remote-controlled vehicle equipped with sonar that made rare videos of an eruption of methane gas from an undersea mud volcano.
Robinson was on watch Thursday morning when he noticed yellow signals on the green sonar monitor, indicating the kind of terrain consistent with an ancient shoreline.
Wave action and ocean currents had eroded much of the area. But members of the expedition hoped to find the suspected shoreline intact in areas where rapidly rising water could have inundated the land as temperatures rose.
The submarine zigzagged over an area about 6 miles long that had the appearance of an ancient coastline cut by streams, Robinson said.
If further study shows that it was a shoreline 20,000 years ago, scientists will look for evidence of human habitation.
The expedition's chief scientist, Dwight Coleman, said the suspected shoreline is about 100 miles south of Galveston and about 80 miles off the coast of Louisiana in about 300 feet of water.
Any discovery of human habitation in the area would push back the earliest known date of human life in North America by about 8,000 to 10,000 years, Coleman said.
Explorers return empty-handed
By Leigh Jones
The Daily News
Published March 13, 2007
GALVESTON — The underwater explorers who spent last week scouring the offshore continental shelf for signs of 19,000-year-old human habitation sailed back to Galveston empty-handed Saturday.
The crew of geologists, biologists and marine archeologists was hoping to find clues of human activity in the area during the last Ice Age, when they believe the Texas coastline extended 100 miles into the Gulf of Mexico.
The expedition did not turn up anything definitive, but the scientists did find what they believe to be signs of the ancient shoreline about 330 feet below the ocean’s surface.
“A series of long vertical steps look like they may have been created by the movement of waves, which carve out a trough and deposit material farther up,” wrote team member Todd Viola, who posted mission logs daily on the expedition’s Web site. “This is the same profile we see on modern beaches.”
Viola described the find as very exciting but noted further exploration would be necessary to verify the scientists’ theory.
Last week’s expedition, dubbed “Secrets of the Gulf,” was headed by Robert Ballard, the oceanographer and explorer best known for his discovery of the Titanic in 1985.
The team traveled from Galveston to the Flower Garden Banks, the northernmost coral reef on the United States continental shelf, aboard the SSV Carolyn Chouest with the U.S. Navy’s nuclear-powered research submarine in tow. It was the first expedition Ballard led from shore.
Using a shipboard television studio and satellite technology, the team transmitted live video feed to groups of scientists all over the country. They also produced five live informational broadcasts each day.
According to the mission logs, the short expedition was plagued by bad weather and technical difficulties that limited use of Ballard’s underwater research capsule, Argus. When it finally entered the water, the remotely operated vehicle transmitted high-definition pictures of the ancient shoreline on the last day of the trip.
While Argus was out of commission earlier in the week, the team relied on images from the submarine. Two scientists at a time stretched out in the bottom of the 145-foot vessel and peered out of view ports to observe the ocean floor.
The submarine’s unique construction — with wheels for driving along the seabed — allowed the scientists to scrutinize the reef from a depth of 40 feet.
The discovery of an active mud volcano created quite a stir, wrote submarine captain Rick Panlilio in a March 6 log entry.
“We imaged it first with our side scanning sonar and found a large crater about 50 yards across on the summit,” he wrote. “The summit was about 160 feet up from the surrounding plane. On the sonar images, we could see a wisp of something trailing off the top of the mound.
“We thrusted the submarine down on top of the hill and crept toward the center and, ‘Eureka!’ we found that the dormant volcano was highly active, with a constant jet of gas, brine and silt being ejected from a briny mud pool inside the crater. The rocky structure inside the crater was jagged and run through with small canyons where dense brine seeped out.”
The submarine and its crew sailed back to Galveston on Saturday. The scientists returned to their labs, but the Navy crew will remain in port until they leave for their next expedition Thursday.
During their layover, Lt. James Krohne said the sailors would be taking a trip to the Johnson Space Center to compare notes with the astronauts.