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A storm approaches. |
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 AMNH Expedition Journal, 9/18/97  Stowed for the storm.
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 n last fall's scouting expedition, researchers and engineers scoped out the Mothra field of black smokers and selected several sulfide chimneys to retrieve during this summer's voyage. The chimneys in the target area aren't expected to have grown much in the last year, but no one knows for sure. Chimneys and larger sulfide structures in other areas can grow as fast as a meter every three or four days. So much is still unknown about these chimneys, since they were only discovered 20 years ago, and one of the research goals is to learn more about how chimneys form, by examining their inside "plumbing". This summer, when the lights of the Canadian remotely operated vehicle ROPOS reveal the chosen chimneys, will they have changed much? We'll all have to wait and see! |
 AMNH Expedition Journal, 9/24/97  Black Smoker
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 AMNH Expedition Journal, 9/16/97 | |
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How hot is that? Well, at sea level, water boils at 100° C, so these fluids are two to three times that hot. The extreme pressures at this depth keep liquid seawater from turning to steam, as it would at the surface! Engineers must consider these extremely high temperatures when figuring out which materials to use close to the vent fluids. Otherwise, they could totally toast the tools! |  Black Smoker | |
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esearch at sea is always at the mercy of the weather. When the wind and waves are too severe, it becomes difficult to work on a moving deck. In extreme cases, equipment can get lost or people injured, so operations may be interrupted for several hours or days in a row whenever conditions are too dangerous. No equipment is sent overboard, and things have to be tied down on the ship. It's frustrating for scientists (who may only get a chance to go to sea every few years) to not obtain precious data due to a storm. The cost of renting the ship and equipment is incredibly expensive, so waiting out a storm can run into a lot of money.
eather conditions can change quickly. While equipment may be sent below the surface under sunny skies, conditions can worsen in the few hours it takes to lower or raise the tools. In the northeastern Pacific Ocean, weather data is sketchy, since no land-based weather stations lie to the west to warn of coming storms. Data is limited to bits of information from scattered ships, planes and a few satellites, but there are still huge gaps. During El Niño years (such as this one), more storms often occur at odd times during the summer, and June can have unsettled weather even during normal conditions.
he pressure at 2250 meters below sea level, over a mile below the surface, is enormous--around 3300 psi (pounds per square inch) or over 22,000 Kilopascals (1000 newtons per square meter, or 1 kilopascal=.0145 psi). How much pressure is that? Picture a small car balanced on a stand the size of a postage stamp! Engineers have to carefully choose materials that will stand up to these crushing underwater conditions.
ince active black smokers are basically underwater hot springs, that adds an extra element of danger to their recovery. While the temperature of the surrounding seawater is just above freezing, at 2° C, the temperatures of the fluids pouring out of an active sulfide chimney can be 200-350° C.
