Volcanos Flashcards

1
Q

Mafic volcanism

A

Magma produced from melting rocks in asthenosphere and lower mantle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Factors that control Explosivity

A

Magma viscosity-high=most explosive

Volatile content- high= most explosive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two kinds of eruptions

A

Hawiian and Strombolian

Form from oceanic hotspots divergent boundaries and continental rifts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Hawiian style

How to erupts

A
Effusive- gas poor
Last years to decades 
Polygenic - series of eruptions
Fissure
1. Swarm of EQ as fissure opens
2. Lava extrudes creating curtain fire
3.over hours/days eruptions may localize creating fountain fed lava flows
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Types of Basalt lava flows

A

A’a and Pahoehoe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

A’a

A

Blocky, shape, clunky, high viscosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pahoehoe

A

Smooth, Ropey, low viscosity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Lava tubes

A

Far far

Like a pool

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hawiian style: What volcanos are built from basalt mafic lava flows

A

Shield volcanos

Broad and flat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Strombolian eruptions

A
  1. Localization of hawiian eruption along a fissure
  2. Gases build, gas rich magma erupts in distinct short burst
  3. Magma can increase in viscosity and able to trap volatiles
    Last days to months long
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Strombolian eruptions build what volcanos

A

Cinder cones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Confer cones

A

Cm sized basalt fragments
Occur in clusters
Build overtime from erupted magma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does volatiles content affect eruptions in cinder cones?

A
Lower= lava flow
Higher= fire fountain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly