Introduction
Nonexplosive calderas are found at the summit of large shield volcanoes, including Kīlauea and Mauna Loa in Hawai’i Volcanoes National Park. Unlike summit and resurgent calderas, calderas on shield volcanoes do not form during explosive eruptions. Instead they form when the summit area collapses due to the withdrawal of magma from shallow magma chambers. The magma withdrawal may occur due to flank eruptions in rift zones.
Nonexplosive calderas can form at other basaltic volcanic centers such as Twin Calderas, a long-lived vent in Bering Land Bridge National Monument that was active during the Pleistocene.
Source: U.S. Department of the Interior, National Park Service
