<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
Skip Navigation
Our Terms of Use (click here to view) have changed. By continuing to use this site, you are agreeing to our new Terms of Use.

5.25: Effusive Eruptions

Difficulty Level: Basic Created by: CK-12
Atoms Practice
Estimated2 minsto complete
Practice Effusive Eruptions
This indicates how strong in your memory this concept is
Estimated2 minsto complete
Estimated2 minsto complete
Practice Now
This indicates how strong in your memory this concept is
Turn In

Isn't this an explosive eruption?

This is a strombolian eruption. This type of eruption was named for Mt. Stromboli in Italy. Strombolian eruptions spew lava into the air. But these eruptions do not have a massive explosion. They create lava flows.

Effusive Eruptions

Mafic magma creates gentler effusive eruptions. There is little or no gas. The lava is thin and fluid so that it flows over the ground like a river. Mafic magma pushes toward the surface through fissures. Eventually, the magma reaches the surface and erupts through a vent (Figure below). Effusive eruptions are common in Hawaii, where lavas are mafic.

In effusive eruptions, lava flows readily, producing rivers of molten rock

In effusive eruptions, lava flows readily, producing rivers of molten rock.

Effusive Eruptions Damage

Effusive eruptions rarely kill anyone because they move slowly. People can usually be evacuated before an effusive eruption. Still, effusive eruptions can be destructive. There is not much anyone can do to stop a lava flow from destroying a building or road (Figure below).

Road covered by lava from an eruption at Kilauea in Hawaii

A road is overrun by an eruption at Kilauea volcano in Hawaii.


  • Mafic magma creates effusive eruptions. The pressure builds but the lava flows fairly quietly.
  • Effusive eruptions cause damage but rarely kill anyone.
  • Mafic magma cools into different types of flows like a'a, pāhoehoe, and pillow lava.


  1. Why do mafic lavas flow rather than explode?
  2. Compare and contrast lavas from explosive and effusive eruptions.
  3. Why do effusive eruptions sometimes cause a lot of damage?

Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes
Please to create your own Highlights / Notes
Show More


effusive eruption

Relatively gentle, non-explosive volcanic eruption.

Image Attributions

Show Hide Details
Difficulty Level:
6 , 7
Date Created:
Jan 04, 2013
Last Modified:
Aug 29, 2016
Save or share your relevant files like activites, homework and worksheet.
To add resources, you must be the owner of the Modality. Click Customize to make your own copy.
Please wait...
Please wait...
Image Detail
Sizes: Medium | Original