Tuesday, October 23, 2012

Two Fascinating Volcanoes

Geologists recently concluded a study attempting to figure out whether Mauna Loa and Kilauea are connected.  There has long been speculation that they are connected due to their close proximity.

Read on for some more...


Connection Between Hawaii's Dueling Volcanoes Explained

ScienceDaily (Oct. 23, 2012) — A new Rice University-led study finds that a deep connection about 50 miles underground can explain the enigmatic behavior of two of Earth's most notable volcanoes, Hawaii's Mauna Loa and Kilauea. The study, the first to model paired volcano interactions, explains how a link in Earth's upper mantle could account for Kilauea and Mauna Loa's competition for the same deep magma supply and their simultaneous "inflation," or bulging upward, during the past decade.
The study appears in the November issue of Nature Geoscience.
The research offers the first plausible model that can explain both the opposing long-term eruptive patterns at Mauna Loa and Kilauea -- when one is active the other is quiet -- as well as the episode in 2003-2007 when GPS records showed that each bulged notably due to the pressure of rising magma. The study was conducted by scientists at Rice University, the University of Hawaii, the U.S. Geological Survey (USGS) and the Carnegie Institution of Washington.
"We know both volcanoes are fed by the same hot spot, and over the past decade we've observed simultaneous inflation, which we interpret to be the consequence of increased pressure of the magma source that feeds them," said lead author Helge Gonnermann, assistant professor of Earth science at Rice University. "We also know there are subtle chemical differences in the lava that each erupts, which means each has its own plumbing that draws magma from different locations of this deep source.
"In the GPS records, we first see inflation at Kilauea and then about a half a year later at Mauna Loa," he said. "Our hypothesis is that the pressure is transmitted slowly through a partially molten and thereby porous region of the asthenosphere, which would account for the simultaneous inflation and the lag time in inflation. Because changes in pore pressure are transmitted between both volcanoes at a faster rate than the rate of magma flow within the porous region, this can also explain how both volcanoes are dynamically coupled, while being supplied by different parts of the same source region."
Gonnermann said the transmission of pressure through the permeable rock in the asthenosphere is akin to the processes that cause water and oil to flow through permeable layers of rock in shallower regions of Earth's crust.
"When we fitted the deformation, which tells us how much a volcano inflates and deflates, and the lava eruption rate at Kilauea, we found that our model could simultaneously match the deformation signal recorded over on Mauna Loa," said James Foster, co-author and assistant researcher at the University of Hawaii School of Ocean and Earth Science and Technology. "The model also required an increase in the magma supply rate to the deep system that matched very nicely with our interpretations and the increased magma supply suggested by the jump in CO2 emissions that occurred in late 2003."
Mauna Loa and Kilauea, Earth's largest and most active volcanoes, respectively, are located about 22 miles apart in the Hawaii Volcanoes National Park on the island of Hawaii. They are among the planet's most-studied and best-instrumented volcanoes and have been actively monitored by scientists at USGS's Hawaiian Volcano Observatory (HVO) since 1912. Kilauea has erupted 48 times on HVO's watch, with a nearly continuous flank eruption since 1983. Mauna Loa has erupted 12 times in the same period, most recently in 1984.
"To continue this research, we submitted a proposal to the National Science Foundation (NSF) earlier this summer to extend our study back in time to cover the last 50 years," Foster said. "We plan to refine the model to include further details of the magma transport within each volcano and also explore how some known prehistoric events and some hypothetical events at one volcano might impact the other. This work should help improve our understanding of volcanic activity of each volcano."
Gonnermann said there has been disagreement among Earth scientists about the potential links between adjacent volcanoes, and he is hopeful the new model could be useful in studying other volcanoes like those in Iceland or the Galapagos Islands.
"At this point it is unclear whether Hawaii is unique or whether similar volcano coupling may exist at other locations," Gonnermann said. "Given time and ongoing advances in volcano monitoring, we can test if similar coupling between adjacent volcanoes exists elsewhere."
Study co-authors include Michael Poland and Asta Miklius, both of HVO; Benjamin Brooks of the University of Hawaii; and Cecily Wolfe of the University of Hawaii and the Carnegie Institution of Washington.
The research was supported by the USGS and the NSF. The Kilauea and Mauna Loa GPS networks are supported by grants from the USGS, NSF and NASA and operated in collaboration by the USGS, Stanford University and the Pacific GPS Facility at the University of Hawaii.
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Story Source:
The above story is reprinted from materials provided byRice University. The original article was written by Jade Boyd.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:
  1. Helge M. Gonnermann, James H. Foster, Michael Poland, Cecily J. Wolfe, Benjamin A. Brooks, Asta Miklius.Coupling at Mauna Loa and KÄ«lauea by stress transfer in an asthenospheric melt layerNature Geoscience, 2012; DOI: 10.1038/ngeo1612
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Rice University (2012, October 23). Connection between Hawaii's dueling volcanoes explained.ScienceDaily. Retrieved October 23, 2012, from http://www.sciencedaily.com­/releases/2012/10/121023134810.htm
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Sunday, October 21, 2012

Is It Hot in Here, Or Is It Just Me?

Fascinating article below regarding the Permian Extinction, one of if not the most lethal in earth's history.


Tropical Collapse in Early Triassic Caused by Lethal Heat: Extreme Temperatures Blamed for 'Dead Zone'

ScienceDaily (Oct. 18, 2012) — Scientists have discovered why the 'broken world' following the worst extinction of all time lasted so long -- it was simply too hot to survive.
The end-Permian mass extinction, which occurred around 250 million years ago in the pre-dinosaur era, wiped out nearly all the world's species. Typically, a mass extinction is followed by a 'dead zone' during which new species are not seen for tens of thousands of years. In this case, the dead zone, during the Early Triassic period which followed, lasted for a perplexingly long period: five million years.
A study jointly led by the University of Leeds and China University of Geosciences (Wuhan), in collaboration with the University of Erlangen-Nurnburg (Germany), shows the cause of this lengthy devastation was a temperature rise to lethal levels in the tropics: around 50-60°C on land, and 40°C at the sea-surface.
Lead author Yadong Sun, who is based in Leeds while completing a joint PhD in geology, says: "Global warming has long been linked to the end-Permian mass extinction, but this study is the first to show extreme temperatures kept life from re-starting in Equatorial latitudes for millions of years."
It is also the first study to show water temperatures close to the ocean's surface can reach 40°C -- a near-lethal value at which marine life dies and photosynthesis stops. Until now, climate modellers have assumed sea-surface temperatures cannot surpass 30°C. The findings may help us understand future climate change patterns.
The dead zone would have been a strange world -- very wet in the tropics but with almost nothing growing. No forests grew, only shrubs and ferns. No fish or marine reptiles were to be found in the tropics, only shellfish, and virtually no land animals existed because their high metabolic rate made it impossible to deal with the extreme temperatures. Only the polar regions provided a refuge from the baking heat.
Before the end-Permian mass extinction, Earth had teemed with plants and animals including primitive reptiles and amphibians, and a wide variety of sea creatures including coral and sea lillies.
This broken world scenario was caused by a breakdown in global carbon cycling. In normal circumstances, plants help regulate temperature by absorbing Co2 and burying it as dead plant matter. Without plants, levels of Co2 can rise unchecked, which causes temperatures to increase.
The study, published Oct. 19 in the journal Science, is the most detailed temperature record of this study period (252-247 million years ago) to date.
Sun and his colleagues collected data from 15,000 ancient conodonts (tiny teeth of extinct eel-like fishes) extracted from two tonnes of rocks from South China. Conodonts form a skeleton using oxygen. The isotopes of oxygen in skeletons are temperature controlled, so by studying the ratio of oxygen isotopes in the conodonts he was able to detect temperature levels hundreds of millions of years ago.
Professor Paul Wignall from the School of Earth and Environment at the University of Leeds, one of the study's co-authors, said: "Nobody has ever dared say that past climates attained these levels of heat. Hopefully future global warming won't get anywhere near temperatures of 250 million years ago, but if it does we have shown that it may take millions of years to recover."
The study is the latest collaboration in a 20-year research partnership between the University of Leeds and China University of Geosciences in Wuhan. It was funded by the Chinese Science Foundation.
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The above story is reprinted from materials provided byUniversity of Leeds, via EurekAlert!, a service of AAAS.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:
  1. Yadong Sun, Michael M. Joachimski, Paul B. Wignall, Chunbo Yan, Yanlong Chen, Haishui Jiang, Lina Wang, and Xulong Lai. Lethally Hot Temperatures During the Early Triassic GreenhouseScience, 2012; 338 (6105): 366-370 DOI: 10.1126/science.1224126
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 MLA
University of Leeds (2012, October 18). Tropical collapse in Early Triassic caused by lethal heat: Extreme temperatures blamed for 'Dead Zone'.ScienceDaily. Retrieved October 21, 2012, from http://www.sciencedaily.com­/releases/2012/10/121018141844.htm
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Thursday, October 18, 2012

Interesting News on Jupiter

Long known for its "eclectic" collection of moons, large and small, astronomers have some new ideas about the origins of such a "motley crew."

Read on for more info...



Giant Impact Scenario May Explain the Unusual Moons of Saturn

ScienceDaily (Oct. 17, 2012) — Among the oddities of the outer solar system are the middle-sized moons of Saturn, a half-dozen icy bodies dwarfed by Saturn's massive moon Titan. According to a new model for the origin of the Saturn system, these middle-sized moons were spawned during giant impacts in which several major satellites merged to form Titan.
Erik Asphaug, professor of Earth and planetary sciences at the University of California, Santa Cruz, will present this new hypothesis October 19 at the annual meeting of the Division for Planetary Sciences of the American Astronomical Society in Reno, Nevada. Asphaug and his coauthor, Andreas Reufer of the University of Bern, Switzerland, also describe their model in detail in a paper to be published in Icarus (in press).
Asphaug and Reufer propose that the Saturn system started with a family of major satellites comparable to the four large moons of Jupiter (known as the Galilean moons, discovered by Galileo in 1610). The Galilean moons account for 99.998 percent of the mass in Jupiter's satellite system; although it has dozens of small satellites, Jupiter has no middle-sized moons. The new model may explain why the two systems are so different.
"We think that the giant planets got their satellites kind of like the Sun got its planets, growing like miniature solar systems and ending with a stage of final collisions," Asphaug said. "In our model for the Saturn system, we propose that Titan grew in a couple of giant impacts, each one combining the masses of the colliding bodies, while shedding a small family of middle-sized moons."
Earth is thought to have undergone a similar kind of giant impact, in which our planet gained the last ten percent of its mass and spawned the moon. Just as our moon is thought to be made out of material similar to Earth's rocky mantle, the middle-sized moons of Saturn are made of material similar to Titan's icy mantle, Asphaug said.
"Our model explains the diversity of these ice-rich moons and the evidence for their very active geology and dynamics," he said. "It also explains a puzzling fact about Titan, in that a giant impact would give it a high orbital eccentricity."
Asphaug and Reufer used computer simulations to study the giant impact scenario, and they found that mergers of satellites the size of the Galilean moons can liberate ice-rich spiral arms, mostly from the outer layers of the smaller of the colliding moons. Gravitational clumping of the spiral arms then leads to the formation of clumps with sizes and compositions that resemble Saturn's middle-sized moons.
"These satellite collisions are a regime that is not very well understood, so the modeling opens up new possibilities in general for planet formation," Reufer said.
The proposed mergers might have occurred as the final act in the process of satellite formation. Alternatively, Saturn may have had a stable system of Galilean-like satellites that was later disrupted by the possibly chaotic migration of the giant planets, as described in the popular "Nice model" of the solar system. A late origin has the advantage of explaining some of the most striking features of the Saturn system.
"What makes the Saturn system so beautiful and unique could be its youth," Asphaug said. "While we don't have a preferred timeframe for this origin scenario to play out, it could have happened recently if something came along to destabilize the Saturn system, triggering the collisional mergers that formed Titan. This 'something' could have been the close passage of a marauding Uranus and Neptune, which is part of the Nice model."
Asphaug acknowledged a couple of dynamical issues raised by the new model. The clumps spawned from the giant impacts might get swept up into the accretion of Titan, rather than evolving into separate moons with their own stable orbits. Additional simulations of the dynamical evolution of the complicated, accreting system are needed to further explore and validate the model. But Asphaug said new data from NASA's Cassini mission on the geophysics of Saturn's moons will provide the ultimate tests.
"Our model makes strong predictions for how Titan was assembled, what the middle-sized moons are made of, and how they started out as rapidly spinning clumps of ice-rich material," he said. "So it's testable. These little moons could provide the clues telling us what happened, and when."
This research was funded by NASA, the University of California, and the Swiss National Science Foundation.
Note: A video simulation can be found at:http://vimeo.com/50778094

Sunday, October 14, 2012

Typhoon Tip, 1979


Earth's Strongest, Most Massive Storm Ever

On October 12, 1979, Typhoon Tip generated peak wind speeds of 300 kph and could stretch from Dallas to New York City

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earth's strongest typhoon, typhoonImage of Typhoon Tip at its strongest on Oct. 12, 1979, from NOAA.Image: NOAA

On Oct. 12, 1979, Super Typhoon Tip's central pressure dropped to 870 mb (25.69 inches Hg), the lowest sea-level pressure ever observed on Earth, according to NOAA. Peak wind gusts reached 190 mph (306 kph) while the storm churned over the western Pacific.
Besides having unsurpassed intensity, Super Typhoon Tip is also remembered for its massive size. Tip's diameter of circulation spanned approximately 1,380 miles (2,220 km), setting a record for the largest storm on Earth. The storm's huge diameter was exactly the same as the distance from New York City to Dallas.
A total of 40 U.S. Air Force aircraft reconnaissance missions flew into Typhoon Tip, making it one of the most closely monitored tropical cyclones, according to a post-analysis written by George Dunnavan and John Diercks.
Typhoon Tip slowly weakened before making landfall in southern Japan on Oct. 19, 1979. However, the typhoon was still the most intense to hit Japan's main island of Honshu in more than a decade. Tip claimed the lives of 86 people and injured hundreds of others.
The extreme winds of Tip knocked over a gasoline storage tank, causing an explosion and fire that spread rapidly through a U.S. Marine Corps camp at Mt. Fuji. The Associated Press reported that one person was killed and dozens of others were injured.
Typhoon Tip, strongest Typhoon ever
Extensive flooding destroyed more than 20,000 homes in Japan, while hundreds of mudslides occurred.
High-rise buildings in Tokyo swayed from the high winds as the typhoon struck.
Typhoon Tip, strongest Typhoon everImage of Typhoon Tip at its strongest on Oct. 12, 1979, from NOAA.
From AccuWeather.com (find the original story here); reprinted with permission.

Wednesday, October 10, 2012

Falcon 9 Launch

A few days ago SpaceX launched the Dragon capsule to the ISS, thus beginning a new chapter in NASA space exploration.  The first commercial launch to the ISS contracted by NASA, the launch and subsequent trip to the space station appear to have been successes.

The technology and exploration is fascinating.  Perhaps this is even more interesting to me since a former student of mine works for SpaceX and is actively involved with both the Falcon and Dragon.

The video below is of the most recent launch on 10/7, 2012.