Today's sampling site was the newly opened Borinquen Hotel, which provided us with an opportunity to observe a relatively new industry emerging in Costa Rica, unofficially known as "geotourism." The health benefits of hot springs have been touted for thousands of years, and spa resorts date back at least to ancient Rome and feudal Japan, if not much earlier.

In Costa Rica, entrepreneurs are now combining an already thriving ecotourism industry with luxury health spas, providing visitors with a unique combination of adventure and relaxation. Today's program, however, was interrupted as we experienced first hand the consequences of the subduction process - an earthquake. Dave reports:

When collecting gases at the Borinquen Hotel spa on the flank of Rincon de la Vieja volcano today, the ground started rolling back and forth with a seemingly low frequency of about a second. The shaking continued for about 40 seconds before tapering away. I was standing on a concrete platform which seemed to attenuate the motion. When the ground stopped moving the entire party stood silent for a second and I instinctively looked at my watch. The event happened at 11:36 am local time.

Within the hour Guillermo had contacted the ICE observatory and reported that a 7.9 earthquake hit El Salvador at the above-noted time. The event took place some 800 km (500 miles) from Rincon. Initial reports are of some 40 deaths - a figure which is expected to rise. The mood in our party is somber. We offer our condolences to families and friends of the victims.

Today's sample at Rincon was the last of our Volcano Expedition. During the past 10 days, we have collected 33 geothermal gas and water samples as well as 14 rock samples (lavas, ashes, and pyroclastic flows). We sampled all five of the presently active volcanoes of Costa Rica - Turrialba, Irazu, Poas, Arenal and Rincon de la Vieja. Due to the guidance of our local expert, Guillermo, and the logistical support of his colleague, Chico, this has been an exceptionally successful collecting trip. The entire party is tired and looking forward to returning to the capital, San Jose, tomorrow. We have many memories of the trip (which we'll share with you tomorrow). It's going to be a fascinating time back in the laboratory.