Don Swanson of the USGS Hawaiian Volcano Observatory calmly told us to be afraid—be very afraid—of the gentle-appearing Kilauea volcano on the island of Hawaii. Well, he may not have sounded so dire. But he did want us to know that Kilauea had very long-term explosive periods in the past and will likely again, threatening the local population and the 5,000 daily visitors to Hawaii National Park.

The Big Island’s volcanoes are known for their beautiful lava flows, and Kilauea is no exception. But looking at the past using carbon-dating techniques, Swanson and his team have found that for the last 2,500 years, Kilauea had been more explosive (60%) than gentle lava flowing.

The first explosive period lasted for about 1,200 years—from 200 BCE to 1000 CE. The second, more recent period, for the 300 years from 1500 to 1800, exhibited “scores” of explosive events, according to Swanson.

Pele, the ancient Hawaiian goddess of volcanoes, displayed her temper by throwing rocks—perhaps causing these explosions, Swanson mused.

The most lethal eruption known from an American volcano occurred at Kilauea in 1790. Most likely, several hundred people died, but contemporary accounts vary. A battle at the time, between the warriors of Keoua and Kamehameha, put several men near the summit at the time of the eruption. According to Swanson’s presentation, “the conditions of the bodies suggests that a pyroclastic density (known as a “PDC,” but often just called a surge) engulfed the victims.” PDCs are a mixture of hot gas and volcanic ash that travel at hurricane velocities.

Footprints were found in the muddy volcanic ash, and in Swanson’s dramatic fashion, his presentation reported, “They could record someone’s last footsteps.”

Swanson wants us to be aware that it could happen again and without much warning. And not just as little blips: Kilauea could be explosive for very long periods of time, as the historic record shows. While Swanson and other scientists are unable to predict the occurrence of damaging eruptions well in advance, small earthquakes and rock-fall are likely to precede the events, allowing time for evacuation.

Moral of the story: Don’t be fooled by the gentle beauty of Hawaii’s lava-flowing volcanoes. Pele still has some rocks up her sleeve!

Last week, MIT scientists, publishing in Science, reported that instead of a vertical plume of magma rising from the Earth’s mantle below the island chain, a more horizontal “hot bed”, several hundred miles west of the island chain, is the source of the islands and volcanoes.

The formation of these volcanic islands has long been a deep mystery to scientists. The volcanoes are well-studied because, they are oddly located in the middle of a tectonic plate rather than the edge where tectonic plates meet.

The leading theory of a vertical plume originated in 1971, and National Geographic breaks it down for us:

As Earth’s crust slid over the plume, as if on a conveyor belt, the erupting seafloor built mounts, mountains, and islands out of layers of cooled lava over tens of millions of years—or so the conventional wisdom goes.

But the recent study blows that theory out of the water.

The researchers found not a plume but, as Science News refers to it, a pancake—a large pancake! It’s 700 km (or 410 miles) below the surface (shallow by volcanic formation standards—a vertical plume would be four times that) and up to 2000 km wide.

In order to have formed the Hawaiian Islands, the pancake would need to somehow heat the surface, spurring volcanoes. It’s possible that molten rocks could be bubbling up from the easternmost edge of the pocket like a lava lamp, says [co-author Robert] van der Hilst, a geophysicist at MIT.

Nature News gives the details behind this new theory:

They gathered seismic data from some 4,800 earthquakes recorded at stations around the Pacific Ocean, and included nearly 170,000 reflected seismic waveforms in their analysis, which incorporated a technique commonly used in oil and gas exploration. Next they applied mineral-physics models of how different minerals behave at different pressures and temperatures to predict the temperature at the subsurface regions that reflected seismic waves, and inferred the existence of a huge, hot region west of the islands.

Many scientists are not convinced of this new pancake theory. Seismologist Edward Garnero of Arizona State University told Science Now that it “is a prediction about the Earth. Let’s see how it holds up.” Only time (and maybe a little syrup) will tell…

Image: NASA

Earth

The Gulf oil spill—the number of gallons spilled and the controversy surrounding the damage seems to top many lists this year. Nature even named Jane Lubchenco, head of NOAA, its newsmaker of the year for how she handled the crisis.

Natural disasters often took the front page in 2010 with the Haitian earthquake and the eruption of Eyjafjallajökull topping many lists. The hard-to-pronounce Icelandic volcano also made many of the best science images of the year lists.

DiscoveryNews ends the year on a positive note with “How Humans Helped the Earth in 2010,” a slide show with text concerning recent strides in alternative energy, species and habitat conservation efforts and individual efforts to go green (electric cars, white roofs and saving energy).

For more environmental news of the year, New Scientist’s Short Sharp Science has a great review and the Nature Conservancy has a best/worst list on its site.

Life

Teeny, modified life stole the spotlight this year—the J. Craig Venter Institute’s so-called “synthetic cell” and GFAJ-1—the bacteria that incorporates arsenic into its DNA—or so NASA scientists claimed.  Science writer Carl Zimmer discredited the arsenic bacteria paper on Slate; NASA author Felisa Wolfe-Simon defended herself in Science. Fun stuff!

The spread of pesky bedbugs was number six in Discover’s “Top 100 Science Stories of 2010.”

Nature’s great article this past summer on eradicating mosquitoes was among its readers’ top choices of the year.

Looking for something a little bigger and less controversial? New Scientist has “The coolest animals of 2010,” which includes a scorpion-eating bat and a fly thought to be extinct for over 160 years!

NPR found it was a very good year for Neanderthals—their genome was sequenced, brain examined and diet expanded.

Remarkably, the Census of Marine Life tops the BP oil spill in the Deep Type Flow blog’s biggest marine science stories of the year for its sheer numbers:

…over 500 research expeditions covering every ocean, over 2,500 scientists and the discovery of over 6,000 species new to science and published in over 2600 peer-reviewed papers.

Space

ScienceNow’s most popular story of all time, not just 2010, was “Does Our Universe Live Inside a Wormhole?” A wonderful theory that we also covered last spring.

Exoplanets, in part thanks to the Kepler mission, were all over the news this year—whether it had to do with size, atmosphere or number within a star system. Discover’s interview with local exoplanet hunter (and California Academy of Sciences Fellow) Geoff Marcy made number 11(!) on their 100 top stories list.

A little closer to home, Jupiter’s missing stripe and Neptune’s tale of cannibalism are included in New Scientist’s most popular space stories of 2010.

Our Moon and Saturn’s moons made news throughout the year and the top lists on Universe Today and Wired this week.

Universe Today also included SDO’s new views of the sun in their top stories list. Stunning!

Hubble celebrated its 20^th year in space this year by taking even more beautiful images. Several are included in Bad Astronomy’s “Top 14 Astronomy Pictures of 2010.”

Technology

Electric cars and NASA’s new foray into commercial spacecraft are included in Scientific American’s top ten stories of the year.

The Large Hadron Collider was very busy this year, and topped many lists. Another machine at CERN made news (and also topped Nature’s readers’ choice list) when it was able to capture antimatter for a sixth of a second!

Graphene not only garnered a Nobel Prize this year, the material (and it’s potential) also made news and top science lists of the year.

DiscoveryNews put plastics on their 2010 list—whether its finding new ways of removing plastic from the oceans or engineering smarter plastics.

What was your favorite science story of the year? Share with us by adding it to the comment section below!

Image by Les Stone, International Bird Rescue Research Center/Wikipedia

A team of scientists from Indiana, England and Ethiopia studied volcanic activity occurring in the remote Afar desert of Northern Ethiopia between 2005 and 2009. The area is right between the African and Arabian tectonic plates and a hotbed for volcanic activity.

The scientists studied a rare sequence of 13 magmatic events —where hot molten rock intruded into a crack, or large volcanic dyke, between the African and Arabian plates. They found that the location of each intrusion was not random.

Volcanic dykes are created when magma seeps from underground through rifts in the surface of the earth. The first one in the series of these events erupted in the Afar desert in September 2005.

In that eruption, the magma was injected along the dyke between depths of two and nine kilometers (between one and five and a half miles), and altered the tension of the earth.

The team was able to watch the 12 smaller dykes that subsequently took place in the same region over a four-year period. By monitoring levels of tension in the ground near where each dyke was intruded they found that subsequent eruptions were more likely in places where the tension increases.

The researchers believe that this sort of domino effect could take place in other volcanic areas.

Lead author, Dr. Ian Hamling said, “If you look at this year’s eruptions at Ejafjallajokull in Iceland, by estimating the tension in the crust at other volcanoes nearby, you could estimate whether the likelihood of them erupting has increased or decreased. Knowing the state of stress in this way won’t tell you when an eruption will happen, but it will give a better idea of where it is most likely to occur.”

Creative Commons image by filippo_jean

Iceland, known as the land of fire and ice due to its glaciers and volcanoes, is one of the most volcanically active regions in the world, with eruptions on average every five years. Because the volcanoes often erupt under ice sheets, they provide very little warning. Heating the overlaying ice sheets and glaciers can also cause major flooding and mudslides after eruptions—that’s what sent the 500 residents around the volcano from their homes on Saturday.

While most residents have now returned safely to their homes, volcanologists are tracking Eyjafjallajökull and its neighbor to the east, Katla.  Katla is one of Iceland’s largest volcanoes and previous eruptions of the smaller Eyjafjallajökull have triggered Katla to erupt.

This is causing increasing fears of flooding; following a 1755 eruption of Katla, a flood the size of the Amazon is said to have discharged.  Since Katla is far from a population center, it would be unlikely to kill anyone, were it to erupt.

But scientists are concerned about more than just flooding. A large eruption in Iceland could also release dust and gas into the air. In 1783, another large Icelandic volcano, Laki, released sulfur dioxide into the air causing smog, changing weather patterns and killing animals and people throughout the country and northern Europe.

Creative Commons image by Andreas Tille