Public Release:  Long Lava Flows May Have Taken Years, Causing Global Cooling And Extinctions

October 26, 1998

AGU RELEASE NO. 98-34

WASHINGTON, D.C. - A multidisciplinary group of scientists is challenging the century old theory that long lava flows must be formed by massive, but short lived, volcanic eruptions. Their research, reported in the Journal of Geophysical Research, suggests that some ancient flows of up to 100 miles in length built up gradually over years, rather than quickly in just days. This finding could have broad implications for the study of Earth and nearby planets.

One result of long but slow moving lava flows may have been global cooling caused by continuing emissions of sulphur dioxide. This cooling could have caused many major extinctions during the past 500 million years. For example, a major eruption in the North Atlantic might have wiped out most dinosaurs by eliminating their plant food supply, even before the presumed asteroid impact that finished the job.

The study is not limited to Earth. Lava flows significantly longer than any known on Earth have been observed on Venus, Mars, and the Moon, and their excellent exposure, coupled with improved spacecraft imagery may actually make them easier to study.

The latest findings on long lava flows are reported in the November 10 issue of the Journal of Geophysical Research, published by the American Geophysical Union. A special section of the journal is devoted to follow-up studies developed from an AGU conference at James Cook University in Townsville, Queensland, Australia. The meeting brought together volcanologists working on active flows in various parts of the world, other volcanologists analyzing flood basalt lava flows, planetary geologists, marine geologists, theoreticians, and economic geologists studying ancient ore-bearing lava flows.

The duration of a lava flow affects the amount of sulfur dioxide released into the atmosphere and therefore the degree of global cooling it causes. This cooling effect was noted following the relatively small eruption of the Laki volcano in Iceland in 1783. Therefore, the study of both active lava flows and ancient long lava flows can help in the assessment of future hazards. For example, there is now is an increased awareness of the role of lava tubes, through which molten lava can be transported over great distances with little loss of temperature. These tubes may play a role in future volcanic eruptions by carrying large amounts of lava to distant populated areas, as they have in the past.
-end-
Note: A limited number of copies of this issue of JGR will be available to news media, but not in advance of publication on November 10. The special section comprises around 200 pages and 17 papers. Please call or email Harvey Leifert to reserve a copy. ###
-end-


American Geophysical Union

Related Volcanic Eruptions Articles from Brightsurf:

New drone technology improves ability to forecast volcanic eruptions
Specially-adapted drones developed by a UCL-led international team have been gathering data from never-before-explored volcanoes that will enable local communities to better forecast future eruptions.

Volcanic eruptions may explain Denmark's giant mystery crystals
Researchers have long been stumped for an explanation of how tens of millions of years-old giant crystals known as glendonites came to be on the Danish islands of Fur and Mors.

The testimony of trees: How volcanic eruptions shaped 2000 years of world history
Researchers have shown that over the past two thousand years, volcanoes have played a larger role in natural temperature variability than previously thought, and their climatic effects may have contributed to past societal and economic change.

Indian monsoon can be predicted better after volcanic eruptions
Large volcanic eruptions can help to forecast the monsoon over India - the seasonal rainfall that is key for the country's agriculture and thus for feeding one billion people.

Volcanic eruptions reduce global rainfall
POSTECH Professor Seung-Ki Min's joint research team identifies the mechanism behind the reduction in precipitation after volcanic eruptions.

A new tool to predict volcanic eruptions
Earth's atmosphere is made up of 78% nitrogen and 21% oxygen, a mixture that is unique in the solar system.

Oral traditions and volcanic eruptions in Australia
In Australia, the onset of human occupation (about 65,000 years?) and dispersion across the continent are the subjects of intense debate and are critical to understanding global human migration routes.

'Crystal clocks' used to time magma storage before volcanic eruptions
The molten rock that feeds volcanoes can be stored in the Earth's crust for as long as a thousand years, a result which may help with volcanic hazard management and better forecasting of when eruptions might occur.

Super volcanic eruptions interrupt ozone recovery
Strong volcanic eruptions, especially when a super volcano erupts, will have a strong impact on ozone, and might interrupt the ozone recovery processes.

Rare volcanic rocks lift lid on dangers of little-studied eruptions
Unusual rocks discovered on a remote mountainside have alerted scientists to the dangers posed by a little-studied type of volcano.

Read More: Volcanic Eruptions News and Volcanic Eruptions Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.