Apollinaris Patera and Tyrrhena Patera

Apollinaris Patera and Tyrrhena Patera

. These Martian volcanoes, imaged by cameras on Viking 1, are of the patera type, with low summits and broad flows. The summit caldera of Apollinaris Partera (left) is 80 thousand meters wide, and the lava flows on its flanks occurred, on average, about a billion years ago. Tyrrhena Patera (right) is low-lying, fractured and highly eroded, with an estimated age of about 2 billion years. The caldera, about 12 thousand meters across, is surrounded by a fracture ring about 45 thousand meters in diameter. Several channels extend outward as much as 200 thousand meters from the volcano center. The volcano could be comprised largely of ash flows, in contrast to the towering, younger shield volcanoes which are mostly lava (Fig. 2.30). In Greek mythology, Apollo is the god of prophecy, sunlight, music and healing, and patera is an ancient Roman term meaning a "broad flat saucer or dish". The Tyrrhenian Sea is located between Italy and Sicily. (Courtesy of JPL and NASA.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University