Expedition to the Mariana forearc

Mar. 23 - May 4, 2003

Emails from the ship

Answers to some of your emails!

This first set of emails is from Lisa Marie Powell from Guam.

What is the relation between Guam and Maug, since GUAM spelled backwards is MAUG?

About "Maug" and "Guam," I often wondered about that too. If we can find out what the two words mean maybe we can figure out if there is any relationship.

What kind of underwater life is found down below?

Life down below: There are all sorts of jellies and plankton in the water column and when we are down there with the ROV we see beautiful fish and sea hares swimming around, but on the seafloor itself, at the seeps were fluids are leaking out of the mud volcanoes is where we see the most interesting animals. There are mussels nestled in cracks in the seafloor and snails, a few crabs and some worms that make tubes for themselves. We don't have a specialist in these kinds of critters aboard, but we are planning to take some cores near the seeps and the muds contain microbial (microscopic) life forms. We do have a microbiologist aboard who will be working with these small animals.

Where is, or what happened to, the title "Ooze Cruise"?

Your teacher Ms. Tatreau told us about your voting for the title "Ooze Cruise" for this expedition. We think that is pretty cute, but it doesn't tell people exactly what we are doing. We picked the less imaginative, but more descriptive title "Mud Volcanoes from the Mantle" to let people know right off the bat what we are studying. Did I say bat??

Is is too dangerous to be down there where you all are with the expedition?

Actually some of us have been down on the seafloor in a submersible that is operated by the Japanese Marine Technology Center (JAMSTEC). The submersible is called Shinkai ("deep sea") 6500 because it can dive to a depth of 6,500 m. Diving in the Shinkai 6500 is very safe. So, no it really isn't too dangerous to be down on the seafloor. At least not if you are not claustrophobic.

Is there a possibility of an underwater volcano erupting around you during this expedition?

It is always possible that an underwater mud volcano might erupt while we are near it. We really do not know how these mud volcanoes erupt, but from what we can see of the currently active vent sites, it doesn't look as if they act explosively. Now, the arc volcanoes are another matter. Some of them have big calderas (large summit craters) and must have explosive eruptions. It is hard to predict whether one will erupt. There are sometimes enough earthquakes under a volcano before it erupts to give you some warning, but even with volcanoes above sea level it is hard to tell exactly when they are going to erupt or how big the eruption is likely to be.

Should there be any concern for the expedition at this time during the war?

Concerns about the war: We are listening to radio and some people are receiving news in email messages from their families. We are all concerned for the safety of the soldiers involved. This is not a happy time for anyone involved, but we do not anticipate that the actual work of the expedition will be affected by the war.

Patty

 

This second email is from Ms Mearig from Honolulu, HI

What's the difference between volcanoes that we have in Hawaii and these mud volcanoes?

Hawaiian volcanoes erupt hot lava (molten rock). They are situated over a hot spot in the mantle of the Earth where the mantle rock is melted and rises to form the volcanoes that made up the islands of Hawaii. The lava is very hot (1100 C). The Mariana mud volcanoes that we are studying are erupting a mush of very finely ground up rock (with some larger chunks - up to a meter or two in diameter) that is mixed with fluids (mostly water) released from the subducting lithospheric plate. The erupting muds are very cool compared to lava. In fact, at the seafloor surface the muds are as cool as the surrounding seawater (~3C).