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7 lis 2023 · Three extraordinarily large explosive eruptions in the past 2.1 million years each created a giant caldera within or west of Yellowstone National Park. During these eruptions, enormous volumes of hot, fragmented volcanic rocks spread outward as pyroclastic density currents over vast areas.
- Geology and History
Over the past 2.2 million years, the 17,000 km 2 (6,500 mi...
- Eruption History
Yellowstone's volcanism is the most recent in a 17...
- Geology and History
Yellowstone sits on top of four overlapping calderas (U.S. National Park Service). Volcanism at Yellowstone is relatively recent, with calderas created by large eruptions that took place 2.1 million, 1.3 million, and 640,000 years ago.
Over the past 2.2 million years, the 17,000 km 2 (6,500 mi 2) Yellowstone Plateau has been shaped by explosive eruptions and profound collapse of the ground, enormously thick lava flows, uplift and extensive faulting, and the erosive power of flowing water and ice.
8 lis 2023 · Yellowstone's volcanism is the most recent in a 17 million-year history of volcanic activity that progressed from southwest to northeast along the Snake River Plain.
The biggest of the Yellowstone eruptions occurred 2.1 million years ago, depositing the Huckleberry Ridge ash bed. These eruptions left behind huge volcanic depressions called “calderas” and spread volcanic ash over large parts of North America. Typical Yellowstone Eruption Sequence
The Yellowstone volcanic field was created during three volcanic cycles over the past 2 million years, each culminating in a voluminous explosive eruption creating a large caldera. Yellowstone's impressive array of hot springs and geysers, part of the most vigorous hydrothermal system in the world, is evidence of a still-active magmatic system.
About 16.5 million years ago, an intense period of volcanism initiated near the borders of present-day Nevada, Oregon, and Idaho. Subsequent volcanic eruptions can be traced across southern Idaho towards Yellowstone.
