The Shumagin Islands

The Shumagin Islands

The R.V. Langseth

The R.V. Langseth

How to get like Popeye at Sea

24 July 2011, 05:45


How absurd it would be to tell an ancient oar-rowing slave about an erg machine. An important part of sea tradition is fitness.  In past epochs this was inextricably linked with your job on board: rowing oars in Athenian galleys, hoisting sails on Spanish galleons or shoveling coal in nineteenth-century battleships.  With the twentieth century innovation of oil-fueled engines on ships, propulsion no longer requires manual labor. Thus, while fitness in the past was a convenient method of moving the ship (and avoiding the lash), nowadays one hopes merely to escape the daunting prospect of an expanding belly. Onboard Langseth some of us have developed a workout program...

Near Miss

23 July 2011, 06:40


[Again due to an account error, this post is several days late. It is meant to precede yesterday's post by Hannah.] Today we avoided calamity. At 2 AM, two hours into my watch, Streamer 1 stopped sending us any data. Rather than sloping oceanic crust, the raw data display showed only a terrifying, bar code-like pattern. So, we resigned ourselves to the inevitable and began to reel in the streamer. In the process, we also had to draw in the starboard paravane (the huge metal sheet which helps hold the streamer away from the ship and the other streamer), and one of its supporting ropes snapped. At the same time, one of the engines stalled, clogged with kelp. After ...

Oh the waves...

23 July 2011, 01:46


The seas are a'rockin and a'rollin worse than we've seen so far. Most of us are happily doped up to avoid turning up our own dinners. Suddenly the everyday motions have turned into a hazardous workout - pinballing off walls in the hallway, trying to go up a down staircase, and even bracing against the walls of our bunk to avoid falling onto the floors. For those who did sleep, they woke to an aftermath of overturned trash cans, dangling phones transformed into havoc-wreaking pendulums, and all my belongings strewn about the common room after the suitcases crashed off the shelves. Watch is thankfully uneventful, meaning for the most part things are going well since the ...

Bathymetry and papers

19 July 2011, 23:31


On watch recently we've had the responsibility of editing bathymetry data. The Langseth has been collecting a large volume of multibeam bathymetry data as we travel along our lines. These images of seafloor topography, acquired by measuring the time it takes a signal to travel down through the water, reflect off the bottom, and return to the ship, will help scientists correlate deep structures seen in the reflection data with geologic structures on the seafloor. While the multibeam data are quite good at imaging seafloor topography, they can often include interference which needs to be edited out. An initial filter is applied to the data to catch obvious false reflections...

It's all about the people

19 July 2011, 06:41

Kelly Hostetler

With a daily grind centered around eating, sleeping and watching data, I have realized two main differences between life on land and life at sea: first, the little moments become big, and second, the people become entertainment. I don’t know if it is seismologists? Boats? Boredom? But shoot, people are nice on this ship. Whether it’s opening doors (or should I say hatches), making coffee, delivering yogurt or asking for kitchen requests, people on the Langseth are always thinking of others. And just like the waves from our air guns reflect off the ocean floor, acts of kindness seem to ripple through the Langseth. On to my second revelation, transect by transect, as the...

Quiet Days and Breakfast.

18 July 2011, 07:22


For the first time on the voyage, immoderate seas were upon us this morning.  Twenty-five knot winds white-capped the North Pacific and heavy fog rolled in.  The scientific operations carried on without much ado regardless of the weather.  Primary analysis of the data began - a very small but important first step in processing the massive quantities of data we're collecting. First looks at the the unrefined data are promising, already showing discernible structures and faults within and below the earth's crust.  One image actually contained an section that had been disrupted by a 6.2 earthquake that occurred as we were collecting data!  While the timing warrants cool poin...

Welcome to the Bat Cave

17 July 2011, 20:54


(For Saturday, July 16th) It has happened at last! We are officially DONE working with streamers. Just so you readers back home can get a feel for what we've been up to, try this little visualization exercise. Imagine a 6 ft. tall can of anchovies and a 7 ft. tall blender. Now pour the anchovies into the blender (be sure to scrape out all that precious, gel-like muck in the corners), press “frappe”, and pour the contents of said blender all over your jeans, in between your fingers and a splash down your shirt for good luck. You have now effectively spent 3 hours coiling, moving, and de-collaring streamers. Yummmmm. One long shower and several loads of laundry later,...

Day 5 – Science 1, Ocean 4 (But That “1” Makes All the Difference)

16 July 2011, 06:32


Today, Science won. After deploying the second streamer last night and having to reel it in once again in order to replace yet more sections, all the equipment is now in the water. Every twenty seconds, a blast from the air gun array rattles the Langseth and data pours in from our hydrophone array. Of course, we did have to turn it all off, circle back, and start again due to a plethora of over-eager whales, but data collection is now solidly under way. As night sets in, even if whales approach, we won’t be able to see them and can pretend they are not there. In sum, as our backs ache and fingers thaw: On an equally profoun...

Wave Propagation 101

14 July 2011, 22:04


Today at lunch, several of us realized that, while we mathematically understand how seismic refraction, and thus our experiment aboard the Langseth, works, we did not understand what that math physically meant. The following is a brief synopsis of why and how this whole air gun/hydrophone system works: Over the next few weeks, we aim to map a section of the subduction zone of the Pacific Plate beneath the North American Plate using seismic reflection and refraction. This is achieved by using air guns to generate a sound wave which bounces off the oceanic crust and sediment layers beneath it as well as being bent back up by those layers towards other hydrophones. Sou...

Day 3-On to streamer two!

14 July 2011, 21:40


Last night on the final watch of the day, we finally put out the last of streamer one! The first streamer is over a decade old, so it was expected to have some problems, but nobody expected it to take quite so long. After almost 48 hours of deployment, the last of the cable which tows the first streamer behind the Langseth was put out. The 8km-long streamer exerts tens of thousands of pounds of pressure on the ship, so these final cables are absolutely crucial. The door, which looks like a large metal gate, was also deployed out to a distance of 450m from the ship. The doors hold the streamers apart from each other on either side of the ship. They also keep the streamers ...