Question: How is elevation calculated?
Name: Shawana, Mr. Bledsoe's 8th grade science class
School: Marlin Jr. High, Marlin, Texas
Response: Until recently, elevation was measured using either a barometer or an altimeter. The barometer converts atmospheric pressure into elevation. The relationship is linear, so thinner the atmosphere, the higher the elevation. The altimeter first calculates the time it takes for the signal to leave the instrument, travel to the ground, and return to the instrument (a plane, for example). This time is multiplied by the speed of sound in the air to get the total distance that the signal traveled. We then divide the total distance in half to get the distance to the ground. With the invention of satellites, however, you can use a GPS (Global Positioning System) receiver that calculates your position based on signals sent from several satellites orbiting Earth. This system also has the advantage of giving a highly accurate position in longitude and latitude in addition to elevation. Most planes, ships, boats, and even many cars now carry GPS receivers. To measure bathymetry, or the depth of the surface below sea level, we use the same process as the altimeter, but we use sonar signals instead of radio waves (which don't travel as well in water).



Question: Are you on or near an abyssal plain?
Name:
Ms. Ann Linsley's class
School: Houston, Texas
Response: We actually are on a plateau, but there is an abyssal plain to the east of this plateau off its margin.  An abyssal plain is a flat region of the deep ocean floor, usually at the base of a continental rise.  It is formed by the deposition of turbidity-current and pelagic sediments that obscure the pre-existing topography.


Question: Do the core samples show fault lines?
Name:
Ms. Ann Linsley's class
School: Houston, Texas
Response: We do not anticipate any fault lines showing in these core samples because we believe this is a very stable area with no signs of tectonic activity. If we were in an tectonically active area, fault lines could be seen in the core sample.


Question: What is the size of the core samples?
Name:
Ms. Ann Linsley's class
School: Houston, Texas
Response: A core sample is 9.5 meters long when it comes on to the floor.  On the deck this is cut into 1.5 meter sections, capped, and labeled.  It is cut simply for the ease of handling.  After some tests are run, the core is sliced in half lengthwise, leaving a "working half" from which samples may be taken and materials disturbed.  The other half is the "archive half" which can have only non-disturbing tests run on it.