Packing up and going home

Jingxuan and Jake recover an OBS

At 4:15 am local time today, we emitted the final sound pulse from our seismic source, marking the end of seismic data collection for our cruise.   We’ll spend the next ~6 hours picking up our seismic gear, and then we will begin steaming towards Honolulu.    It’s been an epic, 40-day-long voyage.  We deployed and recovered 70 ocean bottom seismometers for our experiment in water depths as great as ~3.4 miles, picked up 12 OBS deployed for a separate rapid response effort to the activity at Kilauea, and acquired data on over 2000 miles of track lines.  Preliminary onboard processing has already revealed interesting and important geological structures beneath the seafloor that will tell us both about fundamental earth processes that built the Hawaiian Islands and about geohazards for this region.  Although we have been out here for a long time and have collected a really amazing dataset, I still couldn’t help but feel a little melancholy when we turned off all the equipment and began to pull it in. But all good things must come to an end, and it is time to go home!

Todd and Seis (out of picture) start pulling in streamer at dawn

Donna Shillington, LDEO

Comments

  1. UnknownNovember 8, 2018 at 6:54 AM

    Great voyage Donna, pleasure working with you. Looking forward to next season in Alaska !!

    ReplyDelete

Post a Comment

Popular posts from this blog

The Emperors among us

Image
The main lab's view of the last seismic reflection data being collected. Overseeing  them are  drawings of Emperor Jimmu and Empress Suiko. Finishing the seismic reflection acquisition part of our experiment, we find ourselves south of Jimmu Guyot and near Suiko Guyot. The term ‘guyot’ refers to a flat top seamount that was first named by Harry Hess, a pioneer in developing our current understanding of plate tectonics. These features have a similar morphology to the plateaus found in the Western United States with both having a flat terrain on top that is raised above with surrounding areas often by steep slopes. The Hawaii-Emperor Seamount Chain is a great example of the formation of guyots along volcanic chains. Active volcanism is found on the youngest in the chain, currently at the Big Island of Hawaii which sits atop the central Hawaiian hotspot, a small spot in the plate that fuels the volcano from great depths. As the Pacific Plate slowly but steadily moves to t...
Read more

Unspooling seismic streamer

Image
Dan Sousa, LDEO, carrying a 'bird,' which is used to control streamer depth. The streamer reel is in the background. Having finished the deployment of 70 OBS on the seafloor, we spent ~20 hours deploying the other key parts of the seismic gear for our project: a seismic “streamer” and a seismic source.   Seismic streamers are long cables filled with closely spaced hydrophones, which detect small pressure changes associated with passing sound waves.   The streamer for our program is ~10 miles long! It is stored on large reels, which unspool the streamer off the back of the ship and into the water. As we deploy the streamer into the ocean, we attach equipment to it that is used to control the depth of the streamer beneath the sea surface and determine its location behind the ship, which is very important for such a long cable.   The depth controllers have wings that can be pivoted to dive the streamer deeper or bring it shallower, so they are affectionately...
Read more

Thank you thank you thank you

Image
On June 1, we arrived in port in Kodiak, Alaska, marking the end of our expedition. Kodiak greeted us with spectacular vistas of mountains and lush green hills. It’s not called the Emerald Isle for nothing!   Views of Kodiak on our way into port Despite a late departure and some rough weather, it was an enormously successful trip. We collected a suite of fabulous datasets that will help us understand the formation of this 6000-km-long chain of volcanos that have formed across the Pacific plate over the last 80 million years.   Many mysteries remain about the water-covered parts of our planet, particularly in remote regions like our study area, despite the fact that they host truly gigantic structures. Jimmu Seamount is nearly as tall as Denali, the tallest mountain in North America, and much more massive!     Comparison of bathymetry across Jimmu Seamount and elevation across Denali Collecting data that enables us to unr...
Read more