West Coast Expedition
July 20 - August 30, 2002
West Coast of North America
Logbook
July 31, 2002
Log Entry: Today was sunny and bright--but also so windy and with such large seas that today's dive was cancelled. When the seas are large, the launch and especially the recovery of the ROV are difficult and we risk damaging or losing the vehicle. We spent the day hoping for calmer seas and deploying a wax-tipped rock-coring device over the side of the vessel. The corer is designed to smash into the quenched glassy top of a lava flow, shatter the glass and embed the broken glass fragments in a sticky wax that fills a group of small cones that project from the bottom of the corer. In the event that the corer falls over, additional wax tipped cones are arranged around the 227 kilograms of weight that give the lowered core the power to shatter the glass. Each core takes about 2 hours to collect, plus the time to steam to the next site. We have collected four samples during the day and plan to continue with additional sites. The glass samples recovered are small, but are usually large enough to analyze using micro-analytical techniques. The samples will be used to evaluate variations in lava compositions along the northern Gorda Ridge and to relate the compositions to the shape of the sampled volcanic landforms. We are still hopeful that we can dive tomorrow before we steam to Newport, Oregon, but the wind has not abated during the day and continues to blow at nearly 40 knots.
-- Dave Clague
The deck shots sent back from this leg were taken by Sierra and Shana (Jenny wrote most of the captions).
