9 November, 2001

Nov 9th-Arrival Heights

Today we went on a mini field trip to look at one of last year's seismometers. The name of the hill where we were is called Arrival Heights. In the early 1900's, polar explorers used to go up this hill to look for in-coming ships. The view from up here is incredible! The Transantarctic Mountains are simply glorious!

The project that my team is involved in is called TAMSEIS (Transantarctic Mountains Seismic Experiment). The Transantarctic Mountains are different from other large mountain chains in the world because they did not form from two colliding plates. There are no plates subducting underneath the continent of Antarctica. Subduction happens when one plate goes underneath another. Our hypothesis (what we want to prove) is that the pulling apart of the continent is forming the mountains. We will try to prove this by studying the seismic waves that are traveling through the earth. We will record these waves at the seismic stations that we install.

A seismic station has many parts to it. One part is the seismometer. A seismometer contains weights and springs that vibrate as the Earth moves. The vibrating weights and springs generate electric signals that are recorded by a computer. The strength of the electric signals depends on the movements of the earth (earthquakes). The information coming from the seismometer is stored in a DAS (digital acquisition system). The DAS is like a computer that we might find in our classrooms or homes. This information is stored on a hard disk that is located in the DAS. After the seismometer has been in place for a year, someone returns to it and removes the disk. The information on the disk is then analyzed at the lab.

Other parts of the seismic station include:

battery- powers the seismometer

solar panel- uses the sun to generate electricity that charges the battery wind generator-uses wind to generate electricity that charges the battery GPS (Global Positioning System): a clock that records the exact time

A question for my students:

Why do you think we need both the solar panel and wind generator? Why isn't the solar panel enough?

Pictures of the equipment we are using to set up our seismic stations:

Solar Panel

Wind Generator

The seismometer is located in here. It is extremely sensitive to vibrations, so it is very important to handle it with care!

DAS (digital aqcuisition system)

The team looking at a seismic station that was installed last year at Arrival Heights

A view of McMurdo from Arrival Heights

View from Arrival Heights. Notice the tattered flag!