YVO monthly activity update from rim of Yellowstone's Grand Canyon!

Yellowstone Volcano Observatory scientist-in-charge Mike Poland provides the YVO monthly update from the rim of Yellowstone’s Grand Canyon. The V-shaped gorge tells an amazing geologic story. About half a million years ago, a large rhyolite lava flow erupted. Over time, hot water and gases heated by the magma chamber rose through faults in the lava flow. And as it rose, it began altering the rock, changing rhyolite minerals to clay minerals, which created the spectacular colors. The gorge itself was carved during the last glaciation, when ice dammed the river and then failed, many times. The torrents of water carved the canyon and allowed us spectacular view into the interior of an altered rhyolite lava flow. Mike Poland provides an update on activity in Yellowstone during the month of May, which included 72 located earthquakes, continuation of ground deformation trends, and two water eruptions at Steamboat geyser.