Occur with explosive eruptions of molten or solid tephra moving down the sides of the volcano or from the collapse of part of a volcanic cone or lava flow. Speed is dependent upon the density of the current, volcanic output rate & gradient of slope
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Lava Flow
Streams of molten rock that pour from an erupting vent. Distance they travel dependent on temp of flow (550-1400 degrees), silica content, extrusion rate & slope of the land.
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Volcanic Landslides
Large masses of wet or dry rocks & soil that fall, slide, or flow very rapidly under the force of gravity. Originate as massive rock falls or avalanches, which disintegrate during movement into fragments
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Regional Hazards- Water Based
Lahar, Jokulhlaups
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Lahar
Hot or cold mixture of water & rock fragments that flows down slopes of a volcano & typically enters a river valley. Small but grow in volume as entrains anything in its path. Caused via heavy rainfall, emptying a crater lake or melting of snow
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Jokulhlaups
Glacial outburst floods which occur with discharge of large volumes of water, ice & debris. Tend to be located anywhere where water accumulates in a subglacial lake beneath a glacier
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International Hazards- Airborne
Toxic Gases, Ash Falls
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Toxic Gases
Significant amounts of CO2, sulfur dioxide, hydrogen sulfide & halides can be emitted from volcanoes. Depending on conc.=hazardous to all surroundings
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Ash Falls
Produced in explosive eruptions (small particles less than 0.1mm can stay in atmosphere for 2-3yrs). Distance ash travels dependent on height of eruption column, air temp, wind direction & speeds
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Other cards in this set
Card 2
Front
Occur with explosive eruptions of molten or solid tephra moving down the sides of the volcano or from the collapse of part of a volcanic cone or lava flow. Speed is dependent upon the density of the current, volcanic output rate & gradient of slope
Back
Pyroclastic Flow
Card 3
Front
Streams of molten rock that pour from an erupting vent. Distance they travel dependent on temp of flow (550-1400 degrees), silica content, extrusion rate & slope of the land.
Back
Card 4
Front
Large masses of wet or dry rocks & soil that fall, slide, or flow very rapidly under the force of gravity. Originate as massive rock falls or avalanches, which disintegrate during movement into fragments
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