More Geology Answers
Question Library
Ask a question about Geology
Volunteer
Experts of the Month
Expert Login
Awards
About Us
Tell friends
Link to Us
Disclaimer
|
| |
|
|
| |
| | | |
About Keith Patton
Expertise
I can answer questions concerning physical and historical geology, environmental geology/hydrology, environmental consulting, remote sensing/aerial photo interpretation, G&G computer applications, petroleum exploration, drilling, geochemistry, geochemical and microbiological prospecting, 3D reservoir modeling, computer mapping and drilling.I am not a geophysicist.
Experience
I have 24 years experience split between the petroleum and environmental industries. I have served as an expert witness in remote sensing, developmental geologist, exploration geologist, enviromental project manager, and subject matter expert in geology and geophysical software development.
Organizations
American Association of Petroleum Geologists
American Association of Photogrammetrists and Remote Sensing
Education/Credentials
Bachelor and Master of Science
Registered Geologist in State of Texas
| | |
| |
You are here: Experts > Science > Geology > Geology > volcanoes
Expert: Keith Patton - 10/29/2009
Question
what are the factors that influence the characteristics of volcanic eruptions
Answer
Magma type primarily. Shield volcanoes, have low angle cones due to the fact that their magma is basaltic and of low viscosity. It flows readily so pressure does not build up in the volcanoes. Magma has little gas entrained in the magma.
In composite or stratovolcanoes the peaks are steeper, the flanks formed by successive layers of lava flows and pyroclastic flows. These tend to be found where magma is of the more viscous andesitic or rhyolitic type. Lava domes within the volcano are commonly formed allowing gas pressure to build resulting in catastrophic explosive eruptions with pyroclastic flows that can travel hundreds of miles devastating everything in their path. Magma contains lots of gas dissolved into the magma.
Cinder cones form around a single vent when ejected material is blow upward and out resulting in layers of unconsolidated volcanic debris.
These types are typically found along certain plate margins. The first is found along ocean to ocean plate subduction, mid ocean ridge and oceanic hot spot. The second: ocean to continent, ocean to ocean plate subduction, continental hot spot, continental rift. The last: ocean to continent plate subduction and continental hot spot.
The amount of gas entrained is related to the nature of the location. When subduction occurs and includes sediments saturated with water, such as ocean or near continental margin sediments, then the water contributes to the gas dissolved in the magma.
Add to this Answer Ask a Question
|
|
