Once a circular volcano on the northwest edge of Isabela, Volcán Ecuador now stands broken - a large chunk of it is missing, lost to the sea. Only half of the caldera, the large crater or depression at the summit of a volcano remains.

As we towed the MR1 sonar fish less than two miles east of the volcano, we witnessed parts of the ocean floor no one had ever seen before. Did the missing caldera erode gradually into the ocean or did it slide down in one catastrophic event?

Interpreting the maps is half the fun. “It’s still speculative whether or not the caldera collapse was the result of a gigantic landslide,” Denny Geist says.

As Revelle steamed between northern Isabela and Fernandina, we are seeing an impressive display of fascinating features. “We’re finding lava flows far away from land, almost too far away from the volcanoes on the islands, and volcanic cones decorating the submarine flanks in areas where we didn’t expect them,” Dan Fornari explains.

This afternoon, we continued surveying around the small island of Roca Redonda, where again the seafloor surprised us. Along the way, west of Fernandina, the MR1 sonar identified some very reflective features that look like tongues of black lava in the sonar record. “Generally something that reflective should be a fresh lava flow,” Mark Kurz says. “But we don’t know until we sample it.”

In the evening, we watched the sunset turn Roca Redonda brilliant shades of orange and pink. As Mark, Dan and Dennis huddled around the sonar maps to pick our dredge sites, we are wondering what rocks we will pull up tomorrow to help us understand these geologic wonders.

Dive and Discover Water Word Puzzle [Click here for a printable version of Dive and Discover Water Word #1] Click here for the solution.

[Back to top]