Dispatches from Sea >>
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| March 2007 |  Laura Preston, educator, UNH/Salem High School, Salem, NH. |
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| April 2007 | |||||||
April 18, 2007
Needle in a Haystack - by Karen Neely
Imagine you dropped something in the middle of the Pacific Ocean. How would you go about finding it? Would you even bother? How much would it have to be worth before you’d mount a serious search?
This cruise has been about finding the small in the very large. For most of humanity’s maritime existence, entire mountain ranges, longer and taller than anything terrestrial, were virtually unknown beneath the waves. Not until the 1970s was the idea of oceanic ridges and seafloor spreading even suspected.
Now we’re on a new quest. A few years back, several seismometers were placed around parts of the ridge to record earthquake activity. It takes a lot of nerve to willingly drop a $35,000 piece of equipment to the bottom of the ocean. In an ideal world, these objects record data until the research vessel comes back and sends a command telling them to release their weights and float back to the surface. On command, they can also send out a signal that allows the boat to find them and haul them back on board. In the REAL world, the active volcanic ridge they’re meant to be studying erupts and covers them partially or completely in lava, trapping them on the ocean floor.
So we’re trying to un-trap them. The presence of two of these instruments has been visually verified with a towed camera, and we’re hoping that a bit of tugging and beating on the surrounding rock will free them. The third is sending out a signal, so we know it’s functioning and not completely submerged. But we haven’t seen it yet. We’re looking, and trying to close in on its signal. It’s sort of like a big game of “You’re Getting Warmer.” …With a $35,000 payoff.
We’ll find it. I’m sure of it. But even with advanced GPS, an instrument shouting out a “Polo” to our “Marco,” and a deep-sea submersible with three cameras, it’s a difficult prospect.
 The first Ocean Bottom Seismometer (OBS) is found! |
 Jason II pulls it out of the lava. |
 The OBS is released. |
 Spotted at the surface! |
 Welcome home… |
 Bosun Patrick Hennessy and OS Cecile Hall retrieve the OBS from the water. |
 On deck. |
 The damage done to the OBS from being run over by a lava flow a year or so ago. |
 Scientist, Dan Fornari checks it out. |
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