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The JOIDES Resolution was converted in Pascagoula, Miss., in the fall of 1984. She was built in Halifax, Nova Scotia, in 1978 and had previously sailed the world as a top-class oil-exploration vessel. Sometimes in order to understand what's happening on the Earth, you have to go to the bottom of the ocean. By drilling a core — a column of rock and sediment — out of the ocean floor, you can learn about the Earth's past and present. If you look in the right place, you may even be able to understand what wiped out the dinosaurs 65 million years ago. That's what the drilling ship JOIDES Resolution (JR) did in 1997. Brian Huber, a micropaleontologist, was on board the JR off the coast of Mexico the day the dinosaur-age core was brought up from 420 feet below the ocean floor. He and other scientists on the ship were looking for evidence that a giant asteroid hit the Earth just before the start of the "Great Extinction," when dinosaurs and many other species vanished from the Earth. |
The Great Extinction marks the end of the Cretaceous and the beginning of the Tertiary periods of geologic time, known as the K-T boundary, Huber explains. If an asteroid hit the Earth at that time, it would have thrown great clouds of rock and ash into the air. The clouds would have chilled the Earth for so long — a phenomenon similar to nuclear winter — that many plants and the animals that depended on them for food would have died. The rock and ash would have rained down on the Earth and filtered down to the bottom of the ocean for a long time afterwards. If this scenario is correct, then an ocean core that dates from the time of the K-T boundary should have a telltale layer of material thrown up from the site of the impact.
Because Huber studies microscopic fossils to learn about the Earth's history, he was looking for something additional in the K-T boundary — foraminifera. Forams, as they're nicknamed, are single-celled organisms with distinctive shells. Billions and billions of forams have lived in the ocean for 550 million years. Tertiary forams look very different from Cretaceous forams, most of which died in the Great Extinction.
Huber describes the recovery of the K-T core: "We had gathered on the deck when we thought the next core to come up would contain the K-T boundary. When the core was pulled out, a cheer went up because we could immediately see the dramatic change from white Cretaceous chalk to dark gray pebbles from the asteroid impact to light gray Tertiary chalk."
Under a microscope, the forams in different parts of the core were different too. "Based on the age of the core and the age of the dinosaur extinction," Huber adds, "we know that the impact and extinction occurred at the same time. We call the impact 'one bad day' because so much destruction happened so fast. The asteroid was probably going about 35,000 miles an hour when it hit the ocean near what is now the Yucatan peninsula in Mexico."
To become a micropaleontologist, Huber studied geology along with chemistry, physics, and paleontology. He first studied microfossils in Antarctica where, in the ice and cold, he found the remains of a climate that had been warm enough for forests and dinosaurs. His work on the K-T boundary got him the berth on the JR cruise.
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The JR makes six 2-month research trips around the world each year for the Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES), sponsored by 22 countries including the United States. Each trip addresses a different set of scientific issues, such as plate tectonics, global climate change, and sea level change. The ship is staffed by 25 scientists, 20 engineers and technicians, and 65 crew members and drillers. Everybody on board works 12-hour shifts. Directing the Ocean Drilling Program, which sponsors the JR, is Kate Moran. She studied civil engineering and then ocean and geological engineering and did research on the geology of the ocean floor. Now she "makes sure" the JR fulfills its scientific missions and continues to teach us about the Earth's history. You can read more about the recovery of the core that showed the K-T boundary at the "Blast from the Past" Web site from the Smithsonian Museum of Natural History, www.nmnh.si.edu/paleo/blast. You can follow JR's world travels at the JOIDES Web site, www-odp.tamu.edu/resolutn.html. |
The ship can deploy up to 30,000 feet of drill string. |
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