Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Last catastrophic landslide protects Kilauea from next

08.12.2003


Marine seismology reveals Hawaiian volcano’s past, sheds light on future dangers



The Hawaiian Islands are home to the largest documented shoreline collapse in history, an ancient seaward landslide that sent rocks from the island of Oahu to sites more than 100 miles offshore. The avalanche of debris from the northeast shore of Oahu probably occurred between 1.5 and 3 million years ago, and it undoubtedly created one of the largest tsunamis in Earth’s history, a wave large enough to inundate every coastline of the northern Pacific Ocean.

Today, geologists are studying whether seismic and tectonic forces are creating the potential for a similar disaster on the southeast shore of the big island of Hawaii, near Kilauea volcano. The world’s most active volcano, Kilauea is continually growing larger. At the same time, its seaward flank is moving toward the Pacific, currently at the rate of about 10 centimeters per year. Kilauea’s movement takes several forms. Layers of lava and sediment atop the mountain are pulled down by the force of gravity. The entire mountain itself also moves slowly out to sea as magma derived from deep within the earth’s mantle intrudes into the core of the volcano.


"From previous studies, we know that Kilauea is the site of an active landslide, the Hilina slump, which has moved in historic times," said Julia Morgan, assistant professor of Earth Science at Rice University. "We now recognize that Kilauea also experienced a catastrophic landslide in the past, possibly within 25,000-50,000 years, which is quite recent in geologic terms."

The 10-by-15 mile Hilina slump is partially detached from the seaward flank of Kilauea, and is thought to be a candidate for catastrophic collapse. At this week’s fall meeting of the American Geophysical Union in San Francisco, Morgan will present new findings that the debris left over from the last catastrophic landslide on Kilauea is forming a buffer that stabilizes the Hilina slump. Morgan and her colleagues, Gregory Moore at the University of Hawaii and David Clague at Monterey Bay Aquarium Research Institute (MBARI), reached this conclusion after a comprehensive analysis of two offshore seismic and seafloor mapping surveys conducted in 1998 by the Lamont-Doherty Earth Observatory and MBARI.

They found that the most recent collapse on Kilauea involved a detached piece of the mountain that was similar in size to the Hilina slump and located immediately to its northeast. When this section of the volcano slid away, it settled beneath the ocean at the base of Kilauea. As the entire volcano grew and slid oceanward, this debris piled up, much like snow piles up in front of a snowplow. The result is a broad, bench-like, submarine structure that sits at the foot of the mountain, about 15-20 miles off the coast. The downslope edge of the Hilina slump now impinges on the outer bench.

"Based on what we’ve seen, we believe that the outer bench is still growing, and we expect that the buttressing effect it exerts on the Hilina slump will increase accordingly," Morgan said. "This interaction reduces the likelihood of catastrophic detachment of the Hilina slump under present conditions."

However, because the outer bench contains a good deal of loose sediment and debris, it is also subject to catastrophic failure. For instance, the bench is riddled with small-scale faults and fractures. A massive volcanic eruption or a large earthquake like the 7.2-magnitude temblor that hit Hawaii in 1975 could shake the outer bench to pieces. Morgan said there is geologic evidence that something similar occurred on nearby Mauna Loa about 100,000 years ago.


The research was funded by the National Science Foundation, with additional support from Landmark Graphics Corp.

Jade Boyd | EurekAlert!
Further information:
http://chico.rice.edu/
http://www.riceinfo.rice.edu/projects/reno/photos/slope.html

More articles from Earth Sciences:

nachricht Colorado River's connection with the ocean was a punctuated affair
16.11.2017 | University of Oregon

nachricht Researchers create largest, longest multiphysics earthquake simulation to date
14.11.2017 | Gauss Centre for Supercomputing

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>