Ticks

Scientists nicknamed this type of volcano a tick. About 66 km (41 mi) across at the base, this volcano has a flat, concave summit 35 km (22 mi) in diameter. The sides of the volcano are characterized by radiating ridges and valleys. To the west, the rim of the volcano appears to have been breached by dark lava flows that emanated from a shallow summit pit (5.4 km/3.3 mi in diameter) and traveled west along a channel. The black square represents missing data.