Expedition 350 - Izu-Bonin-Mariana Rear Arc

PORTS: Keelung to Yokohama

CHIEF CO-SCIENTISTS: Cathy Busby & Yoshihiko Tamura



EDUCATION OFFICERS: Lesley Allen & Julia DeMarines




The Izu-Bonin-Mariana Rear Arc is a region just south of Tokyo and is bordered partly by the famous Mariana Trench - the deepest trench on Earth! This region is geologically very interesting because it is a very good example of a plate tectonic convergent boundary, where two plates are coming together and one subducts underneath the other. 


Expedition 350 will contribute to the understanding of how oceanic arcs form and evolve and how continental crust forms by drilling in the IBM rear arc to examine three phenomena:

1) Why crust that develops in the Rear Arc is very similar to continental crust in composition but it contains different minerals

2) Why the rocks at the volcanic front are so different to those in the rear arc when they appear to come from the same parent rock

3) Why there is more crust beneath the rear arc than beneath the volcanic front (how does the rock expand so much?).

To understand the evolution of the whole IBM crust, we will drill the Izu rear-arc region west of the modern volcanic front to recover a complete record of rear-arc volcanism from the present back to its likely inception in early Oligocene or Eocene times. The rear arc contains the record of the “other half” of the subduction factory output, and recovering that record is essential to the IBM drilling strategy. 


Are you a teacher or student? Are you interested in how science works? Do you want to know more about the Earth you inhabit? Expedition 350 needs YOU!  We want as many people as possible to join us on board the expedition. We can take you around the ship with us in real time (with the help of a bit of technology) so you can see how inspiring and enthusiastic the  scientists are. You can ask them questions and watch them doing their research!

If you would like to be a part of the trip sign up on the form (link below) at any time to suit your school, class or other group. We will be working 24 hours a day so don't let mere time zones stop you!