Marine seismic studies like ours are routinely done in the oceans using scientific equipment and research vessels outfitted specially for these purposes. Collecting comparable data in a great lake in Africa requires creative repurposing of available vessels and adaption of scientific equipment.
Donna Shillington, Author at State of the Planet
Ideally, seismic stations are sited in remote, quiet locations. But other considerations are important for a good station, particularly security. As a result, we placed most of our stations in towns near schools, hospitals or town halls, where people could keep an eye on them.
Driving around the Rungwe volcanic province in the southern East Africa Rift installing seismometers, we have the chance to observe first hand how geological processes in action create the most dramatic forms at Earth’s surface.
The last time we visited the southern part of the East Africa Rift, we were responding to an unusual series of earthquakes in December 2009 that shook northern Malawi. This time, we return to this part of the rift system as a part of a more comprehensive effort to understand the underpinnings of this continental rift.
At 6:30 am on August 5, the R/V Langseth pulled into port in Dutch Harbor, marking the end of our very successful research cruise. Our steam into port from our study area involved a trip through Unimak pass and beautiful views of Aleutian volcanoes, including majestic Shishaldin. Many things are required to make a research… read more
Although we still have ~3 days of data collection aboard the R/V Langseth to go before we pull in our equipment and head for port, we are already drowning in beautiful seismic data. Following each pulse from the air gun array, the two 8-km-long streamers listen for returning sound waves for 22 seconds. This is… read more
For the last nine days, we have been underway acquiring seismic reflection data to study a plate tectonic boundary offshore Alaska with the R/V Marcus G. Langseth. Now that the initial excitement of deploying all of our seismic gear and watching the first sound waves arrive on our two 8-km-long streamers has faded, we have… read more
One of the core objectives of our project is to image the part of the plate tectonic boundary that locks up and then ruptures to produce great earthquakes. To examine deep parts of the interface between the Pacific plate and the North American plate in the Aleutian subduction zone, we need to go as close to the coast as possible. This is easier said than done.
On July 11, we marked the successful completion of the first phase of our project and embarked on the second. Part 1 involved deploying ocean bottom seismometers and recording air-gun-generated sound waves. We successfully retrieved all of the OBS’s, and the data that they recorded look very exciting at first blush (and contain some surprises!).
After leaving our seismometers on the seafloor offshore Alaska for a few days to record sound waves generated by the air guns of the R/V Langseth, we returned to collect them. The recovery of OBS always involves a certain amount of suspense.