Tag: Langseth

Holidays on the High Seas

by | 12.27.2011 at 5:35pm | 1 Comment
tree_deck

With round-the-clock shifts, there are precious opportunities for Santa to slip onto a research ship unseen. But slip in he did, leaving treats and gifts around the R.V. Langseth to brighten our day.

Retrieving Instruments from the Deep

by | 12.27.2011 at 1:39pm
WHOI OBS is craned on board.

Over the first 22 days aboard the R/V Marcus G. Langseth, we’ve zigged and zagged our way over a 360×240 mile region of the Pacific plate, first dropping instruments to the seafloor, and then shooting airguns to them (see previous posts). The final step is to recover a subset of the instruments:  34 ocean-bottom seismometers [...]

The Art of Sound in the Ocean

by | 12.21.2011 at 10:38am
Float supporting a 9-gun array being deploy aft of ship.  Guns hang below float.  Yellow cables carry compressed air to three identical arrays previously deployed.

The NoMelt experiment aims to image the structure of an oceanic plate, including its deepest reaches up to 70 km beneath the seafloor.  One of our primary means to do so is to create sound (acoustic) waves in the ocean from the ship, and record those waves at receivers on the seafloor, after they have [...]

Deploying Instruments on the Seafloor in the Deep Ocean

by | 12.13.2011 at 9:22am | 2 Comments
Short-period OBS being deployed by WHOI technicians.  Sensor and recording package contained within glass spheres in orange casing.   Anchor hangs from the bottom.

Oceanic plates are born at mid-ocean ridges, where hot mantle rocks are brought very close to the surface, partially melt, and then cool and crystallize. The newly formed rocks move outwards from the mid-ocean ridge, making way for the next batch of hot rock rising from below. Inch by inch, over millions of years, oceanic [...]

Rolling into Open Water in the Central Pacific

by | 12.5.2011 at 8:48pm
The Langseth at dock in Honolulu.  Bridge cabins/labs are to the right; waist-deck where OBS operations occur is in the center; and the large aft streamer platform is on the left.  Top center is the PSO observation tower, over 85 ft above the waterline.

We nicknamed our project NoMelt because we seek to characterize a mature, pristine oceanic plate far from its volcanic origin at a Mid-Ocean Ridge, and away from areas of pronounced volcanism and melting that subsequently alter the structure of the plate.  Our site in the central Pacific fits these scientific needs. However, one downside is [...]

Probing an Oceanic Plate

by | 11.30.2011 at 8:36am | 4 Comments
Google Earth map of the experiment (dubbed NoMelt) in the central Pacific Ocean basin.

Everything that we understand about the rhythms of the Earth’s surface – the slow growth of mountain chains, the creeping expansion of the ocean basins, the abrupt upheaval of a major earthquake, the explosive eruption of a volcano – is viewed through the context of plate tectonics.  This simple yet highly successful model for describing [...]