Volcanoes & Eruptions
These violent events are responsible for most of the casualties from volcanoes in the past 400 years.
What are pyroclastic flows (and pyroclastic surges)?
Ash.
What are volcanoes a danger to jet engines?
This type of monitoring is typically the most important for predicting the pace of volcanic activity.
What is seismic monitoring?
These deadly events are difficult to predict but could happen in volcanic eruptions during rainy seasons where there is a lot of unconsolidated ash or in volcanic eruptions beneath snowpacks.
What are lahars?
This may be produced by large-scale basaltic volcanoes and contribute to the warming of Earth's climate system.
What is carbon dioxide?
Observations based on these are also helpful for understanding volcanic activity but are limited in their usefulness due to cloud cover, snow cover, vegetation, etc.
What are satellites?
This typically forms from repeated eruptions of basaltic lavas and, though large, typically has gently slopes and has the profile of an upside down soup bowl or tea saucer.
What is a shield volcano?
This is the type of plate tectonic association linked with the Cascade volcanoes in the Pacific Northwest.
What are subduction zones?
This gas, upon its release high up in the atmosphere, changes form and serves as a condensation nuclide for making clouds.
What is sulfur dioxide?
These changes in the structure of Earth's crust in a volcanically active region may signify the migration of magmas beneath a volcano.
What is ground deformation? (or inflation?)
This structure is a collapse is formed by the evacuation of a magma chamber and associated with the largest volcanic eruptions.
What is a caldera?
This type of lava may be made by a partial melting of a very wet mantle or from a basalt that crystallizes out some minerals.
What is an andesite?
This is the name for a type of volcanism that is not necessarily associated with plate tectonic boundaries.
What are hot spots? (or what is a mantle plume?)
An eruption of one of these would likely have global consequences.
What is a supervolcano?
Changes in these overall (or their composition), sensed by satellite or direct measurement, may signify an upcoming eruption.
What are gas emissions?
These shield volcanoes are the largest volcanic structures on Earth (and are also the tallest mountains if mountain height is assessed as the elevation above a base level!).
What are Hawaii's Mauna Loa and Mauna Kea?
The ponding of melts beneath the lithosphere or storage in crustal bodies may drive melting because of this mechanism.
What is melting by raising the temperature of the surrounding rock?
This is an example of a hot spot that occurs on a plate boundary.
What is Iceland?
(Note that Hawaii is a hot spot in the middle of a plate!)
These large emplacements of volcanic products over a relatively short time span have been synchronously linked with global extinction events.
What are flood basalts or Large Igneous Provinces (LIPs)?
This scale is used to assess the relative "violence" of volcanic eruptions.
What is the Volcanic Explositivity Index (or VEI)?