Volcano Mid-Ocean Flood Shield Dome Review Table Ridge

small, steep-sided low, broad small mountain, large, steep-sided large depressions extensive o rift valley o mountain, with slopes <5 , 20-30 slopes, mountain, 10's of km wide up to 9,000-m high up to 400-m high up to 3,000-m high up to ~500-m high Eruption huge volumes of lava lava >> pillow lava tephra >> lava tephra + lava lava > tephra tephra >> lava Products (105 to 106 km3) mafic mafic mafic felsic Composition mafic intermediate

Magma low low low low moderate high high Viscosity

% Gas in Magma low low low moderate low to high low to high low to high

Eruption high discharge rate point source & fissure small , large eruption column, dome collapse, multiple fissure-fed submarine flows from multiple fissures "fire" fountains fire fountain pyroclastic flows pyroclastic flows pyroclastic flows Style (Hawaiian) (Strombolian) (Plinian) (Pelean) (ultra-Plinian)

Explosivity low low low low-moderate very high high ultra-high

hydrous (wet) Magma mantle mantle mantle /mantle crustal melting crustal melting partial melting partial melting partial melting partial melting Origin melting

Plate Tectonic "hot spot" Oceanic Convergent margin numerous numerous numerous numerous Setting (mantle plume) divergent margin ( zone)

Columbia River, Mid-Atlantic Ridge, Paricutin, Mt. St. Helens, Mt. Unzen, Valles, Long Valley, Mauna Loa, Kilaeua, Examples Deccan Traps, East Pacific Rise, Cerro Negro, Popocatapetl, Mont Pelee, Yellowstone, Joes Hill Siberian Traps Mid-Indian Ridge Sunset Crater San Francisco Peaks Sugarloaf Mtn Superstition Mtns

blast, ash fall, blast, ash fall, no significant blast, ash fall, blast, Hazards lava flows lava flows pyroclastic flows, pyroclastic flows, hazards lava flows pyroclastic flows mud flows, tsunami

eruptions never some of the largest >70,000 km of form volcanic arcs commonly associated usually monogenetic eruptions rarely observed; role in single mid-ocean ridges around the with stratovolcanoes Comments (erupt once and done) observed mass extinctions(?) on Earth (MORs) on Earth "" and