Hawaiian Islands formed through extrusive volcanic activity

Sep 03, 2013

Scientists generally believe that the Hawaiian Islands formed primarily through endogenous growth, or intrusion, in which hot magma intrudes into a rock and then solidifies before it reaches the surface. However, a new study suggests that the islands may actually have formed primarily through extrusion, which occurs when a volcano erupts and magma reaches the surface and flows away from the eruption site before cooling and solidifying.

Flinders et al. used gravity data from historical land surveys along with recently compiled marine gravity data to estimate the volumes of intrusive material, which can be identified by its higher density, below all of the known volcanoes throughout the Hawaiian Islands.

Contrary to previous studies, which had estimated that intrusions account for about 65 to 90 percent of the total volume of the islands, the authors find that the volcanos of the main Hawaiian Islands are composed of less than 30 percent dense intrusive material, on average. This suggests that the islands are not built primarily through endogenous growth, as had been thought, but rather through extrusive growth.

Explore further: They know the drill: UW leads the league in boring through ice sheets

More information: Flinders, A. Intrusive dike complexes, cumulate cores, and the extrusive growth of Hawaiian volcanoes, Geophysical Research Letters. DOI: 10.1002/grl.50633, 2013 http://onlinelibrary.wiley.com/doi/10.1002/grl.50633/abstract

add to favorites email to friend print save as pdf

Related Stories

High genetic diversity in an ancient Hawaiian clone

Dec 22, 2011

The entire Hawaiian population of the peat moss Sphagnum palustre appears to be a clone that has been in existence for some 50,000 years researchers have discovered. The study is published in New Phytologist.

Hawaii's botanical history is expanded

Apr 21, 2008

Smithsonian Institution scientists say one of Hawaii's most dominant plants, Metrosideros, has existed on the islands much longer than previously believed.

Recommended for you

2014 Antarctic ozone hole holds steady

8 hours ago

The Antarctic ozone hole reached its annual peak size on Sept. 11, according to scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA). The size of this year's hole was 24.1 million ...

New study finds oceans arrived early to Earth

11 hours ago

Earth is known as the Blue Planet because of its oceans, which cover more than 70 percent of the planet's surface and are home to the world's greatest diversity of life. While water is essential for life ...

Magma pancakes beneath Lake Toba

11 hours ago

Where do the tremendous amounts of material that are ejected to from huge volcanic calderas during super-eruptions actually originate?

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.