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Volcanic aerosols from huge volcanoes (VEI>=5) directly reduce global mean sea surface temperature (SST) by approximately 0.2-0.3 °C, [1] [3] milder than global total surface temperature drop, which is ~0.3 to 0.5 °C, [4] [5] [6] according to both global temperature records and model simulations. It usually takes several years to be back to ...
For example, some volcanoes are polygenetic with more than one period of activity during their history; other volcanoes that become extinct after erupting exactly once are monogenetic (meaning "one life") and such volcanoes are often grouped together in a geographical region.
Of particular importance is the prediction of hazardous eruptions that could lead to catastrophic loss of life, property, and disruption of human activities. Risk and uncertainty are central to forecasting and prediction, which are not necessarily the same thing in the context of volcanoes, but both have a process based on past and present data.
In this time span, cratons grew into continents with modern sizes. The change to an oxygen-rich atmosphere was a crucial development. Life developed from prokaryotes into eukaryotes and multicellular forms. The Proterozoic saw a couple of severe ice ages called Snowball Earths. After the last Snowball Earth about 600 Ma, the evolution of life ...
The colloid is somewhat fluidised by the gas, allowing it to spread. Pyroclastic flows can often climb over obstacles, and devastate human life. [3] Pyroclastic flows are a common feature at explosive volcanoes on Earth. Pyroclastic flows have been found on Venus, for example at the Dione Regio volcanoes. [19]
A cryovolcano (sometimes informally referred to as an ice volcano) is a type of volcano that erupts gases and volatile material such as liquid water, ammonia, and hydrocarbons. The erupted material is collectively referred to as cryolava; it originates from a reservoir of subsurface cryomagma. Cryovolcanic eruptions can take many forms, such as ...
Compositional analysis has been very successful in the grouping of volcanoes by type, [9]: 274 origin of magma, [9]: 274 including matching of volcanoes to a mantle plume of a particular hotspot, mantle plume melting depths, [10] the history of recycled subducted crust, [9]: 302–3 matching of tephra deposits to each other and to volcanoes of ...
Tephra is a generalized word for the various bits of debris launched out of a volcano during an eruption, regardless of their size. [4] Pyroclastic materials are generally categorized according to size: dust measures at <1/8 mm, ash is 1/8–2 mm, cinders are 2–64 mm, and bombs and blocks are both >64 mm. [5] Different hazards are associated with the different kinds of pyroclastic materials.