Archive of September 13th, 2007

Teacher at Sea log for Thursday September 13

Today we spent the early hours surveying, and now at 11 am we are entering Honolulu Harbor to pick up the new cable for Jason 2. It will take some time to test the new cable and load it onto the Kilo Moana, so we have little bit of free time on Oahu before we head out to sea again tomorrow morning.

I sent some photos of the Jason 2. The Jason 2 is designed to float above water, so that if it breaks away from its tether it can be recovered. Propellers on top of Jason 2 (that look like fans inside a tire rim) keep it close to the bottom by forcing water up to hold the submarine down.

We learned some of the scientific names for features on the rocks we might see using the cameras on Jason 2. One important job is recording descriptions of what we see through the cameras in a written log. We will keep a log of each and every rock that is picked up and placed in the baskets on Jason 2 and brought to the surface. Here are a few good words to learn: hackly, hyaloclastite, xenolith, anthropogenic, and lobate.

I watched as we pulled in the magnetometer (or "the maggie"), a device that trailed behind the ship collecting magnetic data during the last three days. Magnetic data can be useful in determining if rocks are part of a volcano or a landslide, but it's not safe to leave the maggie out when we're approaching the harbor.

Yesterday I followed up on the rubbish question. The rubbish is sorted and the paper and plastic is burned. It takes three hours to burn each load. I saw the incinerator and it looked a lot like a kiln for pottery. Once they raise it to a high enough temperature everything starts to burn. There is a tiny glass window you can peer through to see the flames, which were a nice orange color. The food trash goes overboard into the sea, while batteries and glass are brought into port and dumped in the rubbish collection bins.

Science Update by Garrett Apuzen-Ito

Thursday, September 13th

Here are two maps of the amazing volcano fields northwest of Ni'ihau and Ka'ula. The colored map shows seafloor depth (blue being deep, red being shallow). The other map shows side-scan sonar data with black representing a loud echoes and white being a soft echoes. Loud echoes come from volcanic rock with little or no sediment cover. Notice the numerous pancake-shaped volcanoes scattered about. The wide areas of black mean that the eruptions here are much younger than Ni'ihau, Ka'ula or Kauai We won't know until we sample and analyze the rocks exactly how old they are. We never expected to see so many volcanoes around these relatively small islands.

Presented by the School of Ocean and Earth Science and Technology at the University of Hawaii, with financial support from the National Science Foundation.