Rocky pillars dotting Iceland’s Skaelingar valley were projectiles tossed into the fields by warring trolls.
A lava pillar in Iceland's Skaelingar valley. A new study suggests that these pillars were formed in an unusual interaction where lava and water met on land without exploding. Credit: Tracy Gregg
That, at least, is the tale that University at Buffalo geologist Tracy Gregg heard from a tour guide and local hiker when she visited the site on two occasions.
But Gregg and a colleague have a new explanation for the presence of the lava formations — this one also unexpected.
In the Journal of Volcanology and Geothermal Research, she and former UB master’s student Kenneth Christle report that the pillars, hollow and made from basalt, likely formed in a surprising reaction where lava met water without any explosion occurring.
Their findings appeared online Aug. 15 and will be published in a forthcoming print edition of the journal.
“Usually, when lava and water meet in aerial environments, the water instantly flashes to steam,” said Gregg, a UB associate professor of geology. “That’s a volume increase of eight times — boom.”
“Formations like the ones we see in Iceland are common in the ocean under two miles of water, where there’s so much pressure that there’s no explosion,” she said. “They’ve never been described on land before, and it’s important because it tells us that water and lava can come together on land and not explode. This has implications for the way we view volcanic risk.”
Deep-sea basalt pillars form when columns of super-heated water rise between pillows of lava on the ocean floor, cooling the molten rock into hollow, pipe-like minarets. The structures grow taller as lava levels rise, and remain standing even after volcanic eruptions end and lava levels fall again.
Gregg and Christle propose that the same phenomenon sculpted the land-based lava pillars in Iceland.
It happened in the 1780s, when lava from a nearby eruption entered the Skaelingar valley, which Gregg theorizes was covered by a pond or was super-swampy.
She thinks one reason no explosion occurred was because the lava was moving so slowly — centimeters per second — that it was able to react with the water in a “kinder, gentler” manner.
“If you’re driving your car at 5 miles per hour and you hit a stop sign, it’s a lot different than if you hit that same stop sign at 40 miles an hour,” she said. “There’s a lot more energy that will be released.”The Iceland formations, some over 2 meters tall, display telltale features that hint at how they were created. For example:
The skin of the towers isn’t smooth, but gnarled with shiny drips of rock. The glassy texture suggests that the lava hardened quickly into rock, at a pace consistent with non-explosive water-lava interactions. Had the lava cooled more slowly in air, it would have formed crystals.
Each of these distinctive characteristics is also prevalent in deep-ocean pillars, said Gregg, who first saw the Icelandic formations in the mid-1990s while hiking in the valley with her husband.
“I knew as soon as I saw them what they were,” she said. “I had, at that time, been on submarine cruises and seen these things deep under the sea, so I was just hysterical, saying, ‘Look at these!’ So I ran around and started taking pictures until the light started running out.”
She didn’t have the chance to return to the site until 2010, when Christle received a student research grant from the Geological Society of America to do field work in Iceland.
The two spent four days studying the pillars in detail, confirming Gregg’s original suspicions.
In the future, scientists could hunt for land-based lava pillars near oceans to learn about the height of ancient seas, or search for such formations on Mars and other planets to determine where water once existed.
Media Contact InformationCharlotte Hsu
Charlotte Hsu | EurekAlert!
Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center
NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences