Dive and Discover : Expedition 9 : Galapagos Rift : Mail Buoy

Return to the Galápagos Rift
Expedition 9:
May 20-June 3, 2005

Mail Buoy
May 21, 2005

My name is Joseph Paduch I am 7 years old and I go to Hammond Elementary School in Onset Massachusetts. I live in East Wareham. My questions are:
Why do you use glass balls for moorings?

Hello Joseph:

What good questions! Here are some answers:

Glass balls are very strong because of their round shape. They are filled with air so that they float. We put them on mooring for two reasons. First, so that the mooring holding the equipment stays vertical when it is set down on the bottom. Second, if we want to recover a mooring without going to the bottom of the ocean, we can send a signal to release its anchors and the glass balls will make it float to the surface.

Why is the volcano active all the time?
The Arenal Volcano you saw in the slide show hasn’t been active all the time. The current phase of activity started in 1968, and it has been erupting large boulders and rocks ever since then. It is active because it is located where one tectonic plate on the eastern side of the Pacific is sliding (or subducting) beneath the plate with Costa Rica on it. This creates molten rock deep in the Earth which rises to erupt at Arenal Volcano. If you want to learn more about this, see Plate Tectonics in the Deeper Discovery section of the Dive and Discover web site.

Thank you for your questions—and I hope you will continue to follow our cruise. Our first dive to the bottom of the ocean is tomorrow!

Susan Humphris
Geochemist

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