Tag Archives: caldera

These sharks thrive in a real-life underwater volcano

It’s not Sharknado, but it’s definitely Sharkcano — researchers have found thriving, active sharks in an underwater volcano in the Solomon Islands near Papua New Guinea.

Life always finds a way; whether we’re talking about tardigrades living in extreme environments, plants in frozen landscapes, or, as it turns out, sharks in a volcano. In January 2014, National Geographic reported the unexpected discovery of several marine species living inside an active underwater volcano caldera, in the Kavachi Volcano in the Southwest Pacific Ocean (around the Solomon Islands). Particularly surprising was the presence of sleeper sharks.

“We were freaking out,” said University of Rhode Island Ph.D student Brennan Phillips to National Geographic.

Thought to be both predators and scavengers, sleeper sharks feed by suction and cutting of their prey. They live in frigid depths, where light is scarce and food is even scarcer. So what on Earth were these creatures doing in the hot, acidic caldera? That’s a good question, which researchers wanted to answer. So scientists went back for another expedition. But how do you explore an environment that’s toxic and hot enough to injure or even kill you? Why, you send in the robots, of course.

“Our goal is to send instrumentation there to get meaningful data, but sometimes it’s really fun to just blow stuff up,” says National Geographic explorer and ocean engineer Brennan Phillips.

Image credits: National Geographic / Youtube.

Phillips reunited with his 2015 expedition mates — Alistair Grinham of University of Queensland and Matthew Dunbabin of Queensland University of Technology and Director of GFB Robotics — to measure pH, carbon dioxide, temperature fluctuations, acidity, and have a glimpse of the location.
“The smaller robots have acoustic depth sounders for gathering bathymetry of the vent region, surface water temperature sensors, accelerometers, and cameras. The larger robots carry greenhouse gas monitoring sensors and measure direct gas release to the atmosphere as well as physical air samples. We also have simple drifting robots that are capable of collecting water samples,” says Dunbabin.

The water inside the caldera is hot, acidic, and turbid. Image credits: National Geographic / Youtube.

They’ve learned that Kavachi is a strong greenhouse gas emitter, water temperatures are ten degrees higher than normal, and the pH drops sharply. The water is also very cloudy. None of these things are really surprising, and they’re all these bad for fish, and but are they equally bad for sharks?
For now, that’s still an open question. While the expedition helped shed more light on the Kavachi situation, we still don’t know how the sharks got there, why they’re enjoying the place so much, and how they will adapt in the future. Can they anticipate an impending eruption? What do they feed on? Those are all still questions that need to be answered. These learnings are now driving the development of new experiments for the next trip, Dunbabin says, and the exploration of Kavachi is far from over. In fact, it may just be beginning.
The Yellowstone caldera (circled in red) in Wyoming is the world's largest super-volcano. Credit: USGS.

Yellowstone supervolcano erupted twice 630,000 years ago

The Yellowstone caldera (circled in red) in Wyoming is the world's largest super-volcano. Credit: USGS.

The Yellowstone caldera (circled in red) in Wyoming is the world’s largest super-volcano. Credit: USGS.

As the name implies, a supervolcano is just like a volcano, only on a far grander scale (ejecta volume greater than 1,000 km3). One of the hallmarks of a supervolcano is that it forms a wide depression called a caldera. New research suggests that not one but two closely spaced powerful eruptions from 630,000 years ago sculpted the massive caldera (72 x 48 km) around the Yellowstone supervolcano. In the aftermath of the two eruptions, which were 170 years apart, global warming was put on hold by the double cooling effect.

Winter is coming

“We discovered here that there are two ash-forming super-eruptions 170 years apart and each cooled the ocean by about 3 degrees Celsius,” said  James Kennett, a geologist at the University of California Santa Barbara, and lead-author of the new study presented at a recent conference hosted by the Geological Society of America.

By peeling off the soil, scientists can learn fairly accurately how a region’s geology looked like, even millions of years ago. They can also use clues to determine not only if there was a cataclysm, such as a megaflood, but also when it happened. Seafloor sediments in the Santa Barbara Basin, which lies off the coast of Southern California, contain two layers of volcanic ash whose chemical fingerprint matches that of Yellowstone’s most recent supereruption.

The ash layers, which scientists call tephra, are sandwiched between sediments that, like time capsules, record information about the ocean and climate change at the time they were deposited.

Both ash and sediments told scientists that the Yellowstone supervolcano’s last eruption, which has been extensively studied, was not a single event. Instead, Kennett and colleagues found evidence of two closely spaced eruptions.

A massive amount of plume, ash, and dust was ejected by both eruptions, creating an atmospheric blanket that let less sunlight reach the planet’s surface. Around 630,000 years ago, the planet was just recovering from an ice age. The eruptions, however, put global warming on hold, causing two planetary winters.

Scientists inferred the temperature in the ocean following the eruption by studying the tiny shells of foraminifera that sank to the seafloor where they were buried and preserved in the sediment. Such shells have oxygen isotopes in their composition which are temperature-depended, revealing the surface temperatures in which the animals lived.

Together, the volcanic ash record and the foraminifera climate readings made it quite clear that the supervolcano eruptions caused two volcanic winters. The onset of the global cooling events was abrupt and coincided precisely with the timing of the supervolcanic eruptions. This was the first observation of its kind.

Kennett adds that the eruptions triggered feedback mechanisms that enhanced the cooling magnitude and duration. For instance, the eruptions might have led to increased sunlight-reflecting sea ice and snow cover or a change in ocean circulation that would cool the planet for a longer time.

“It was a fickle, but fortunate time,” Kennett said of the timing of the eruptions. “If these eruptions had happened during another climate state we may not have detected the climatic consequences because the cooling episodes would not have lasted so long.”

Yellowstone has erupted at least three times before: 2.1 million years ago, 1.3 million years ago, and 630,000 years ago. Geologists think we’re in the ‘right’ timeframe for another eruption. One recent study found the next supervolcano eruption could occur even within decades, with potentially catastrophic consequences for all life on Earth. It could also just as well happen in thousands of years.

Large volcano in Iceland might be set to erupt, temblors warn

After two large earthquakes with magnitudes over 4, the Katla volcano in Iceland seems set to erupt.

Myrdalsjökull glacier, above the volcano. Photo by Chris73.

Iceland’s Meteorological Office said that two unusually large earthquakes struck the crater of Katla, causing at least ten aftershocks. There were no reports of injuries or even property damage, but this could be a warning sign that something big is about to happen at the volcano.

Named after an evil troll, Katla is very active. Over twenty eruptions have been recorded between 930 and 1918, at intervals of 13–95 years. Recently, small eruptions took place in 1999 and 2011, but none of them were strong enough to break the ice covering the caldera.

The last big eruption was in 1918 when the volcano spewed ash for several weeks. This seems to indicate that the volcano is overdue for an eruption as it is, but there are no clear signs of when this is going to happen. Geophysicist Gunnar Gudmundsson said the situation around the volcano is “a little bit unusual” but argued against panic.

“People have been waiting for an eruption for 50 years,” Gudmundsson said. “But there is no sign of an eruption.”

[panel style=”panel-success” title=”Katla at a glance” footer=””]- large volcano in southern Iceland, very active
– has a diameter of 10 km (6.2 mi) and is covered with 200–700 metres (660–2,300 ft) of ice
– twenty eruptions between 930 and 1918, last big one in 1918
– seems overdue for an eruption[/panel]

While Iceland’s Met Office did raise the alarm level, it too said that no clear signs indicate an impending eruption.

“It is quite a dynamic situation now, in the next hours and days following this, but as we speak at the moment we do not see any signs that there is an imminent hazardous unrest about to happen,” Matthew Roberts from the Icelandic Met Office said.

The last major volcanic eruption in Iceland was in 2010 when Eyjafjallajokull volcano erupted, spitting out an enormous cloud of ash and canceling over 100,000 flights. Iceland is one of the most volcanically active countries in the world. The reason for this is twofold: first, it’s due to its location on the mid-Atlantic Ridge, a divergent tectonic plate boundary, and second, due to its location over a hotspot.

Australian Biologists Discover Volcano Cluster by Mistake

A chance discovery revealed an impressive cluster of extinct volcanoes 150 miles off the coast of Sydney, three miles below the water surface. The four volcanoes, which are now calderas, may reveal why Australia and New Zealand separated between 40 and 80 million years ago.

Don’t you just hate it when you go searching for lobsters and you stumble upon massive, extinct volcanoes? Researchers on board a new vessel were hunting for a lobster nursing ground. Not only did they find a surprising breeding ground and map the seafloor, but they also found these volcanoes. Chief scientist Iain Suthers, a marine biologist and professor at UNSW Australia called the mission “enormously successful”.

“Not only did we discover a cluster of volcanoes on Sydney’s doorstep, we were amazed to find that an eddy off Sydney was a hotspot for lobster larvae at a time of the year when we were not expecting them.”

He also expressed admiration for this geological phenomenon, praising it like “something off the front cover of a geology text book”.

“If you could drain the ocean it would be magnificent to see for a few seconds – it’s a remarkable structure,” Professor Iain Suthers told the Australian Broadcasting Corporation.

However, it’s not like they weren’t prepared for any geological discoveries. Volcano expert Professor Richard Arculus from the Australian National University, an igneous petrologist  was also involved in the study, and he believes there is a strong significance to this discovery, potentially offering valuable information about the tectonic evolution of Australia and New Zealand. He said:

“[We are] learning more about the past of Australia and New Zealand and the nature of the stuff below the crust of the earth. It proves yet again that we know more about the topography of Mars than we do the seabed in our own backyard. It could provide information about why the east of Australia stands high, and about mineral deposits, which always drives curiosity.”

This discovery wouldn’t have even been possible without the advanced sonar capabilities of the research vessel. The government’s previous research vessel could only map the sea floor to a depth of about 9 000ft, leaving much of Australia’s oceans uncovered – this one goes much deeper though. The ship can also “send and receive data while we’re at sea, which meant the team back on base at UNSW in Sydney could analyze the information we were collecting at sea and send back their analysis, along with satellite imagery, so we could chase the eddies as they formed.”

“This is the first time we’ve been able to respond directly to the changing dynamics of the ocean and, for a biological oceanographer like me, it doesn’t get more thrilling,” he added. “It was astounding to find juvenile commercial fish species like bream and tailor 150 kilometers offshore, as we had thought that once they were swept out to sea that was end of them. But in fact these eddies are nursery grounds along the east coast of Australia.”

Again, these are not active volcanoes and there’s no chance of them erupting.

Series of earthquakes strike Yellowstone

Seismologists working at the University of Utah reported an earthquake occurring at 06:34 AM on March 30, 2014 (MDT). The epicenter of the magnitude 4.8 shock was located 4 miles north-northeast of Norris Geyser Basin in Yellowstone National Park, Wyoming.

A supervolcano

This was not a singular event, but was a part of a series of earthquakes that began in this area on Thursday, March 27 which included over 25 temblors. This was the largest event to take place in Yellowstone since February 22, 1980.

The Yellowstone Caldera is actually a part of a supervolcano, which erupted in massive events 2.1 million, 1.3 million, and 640.000 years ago. Some geologists believe that the supervolcano will erupt again sometime in the next 50.000 years, but based on the style and location of the earthquakes, there’s no reason to expect any other geologic activity aside for continued seismicity – in other words, you shouldn’t panic or worry of a supervolcano eruption – there’s no indication at all that this could happen in the foreseeable future.

If the Yellowstone were in fact moving closer to an eruption, we would get some more severe warnings. Much higher seismic activity, with events probably going up to a magnitude of 6 and even further would be the first warning sign. Then, we’d see changes in hydrothermal features, gas output, ground movement – all at a very high level, which would leave little cause for ambiguity. But what if an eruption would take place?

Yellowstone fallout ash bed.

Yellowstone fallout ash bed.

It’s unclear just how much magma is crystallized in the Yellowstone Caldera, and if it can still erupt with the strength it did 640.000 years ago, but if it did, the results would be devastating. It almost certainly won’t threaten the human race as a species, but for the US, it would be a matter of survival. People from the surrounding states would have to be evacuated almost entirely to be able to survive, and the nation itself would be under extreme pressure. The entire world would probably experience perpetual winter for a few years, as the volcanic ash blocks the sun rays from heating the Earth – it would be unlike anything the human race has ever faced. This is just something to give you a sense of proportion, not something meant  to freak you out. This is a geologic event; it could tens of thousands of years from now, it could never happen again – but it almost certainly not happen in the foreseeable human future.

Anyone who felt the earthquake is encouraged to fill out a survey form on either the Seismograph stations web site: www.quake.utah.edu or the U.S. Geological Survey web site: earthquake.usgs.gov.

Yellowstone Geyser

New Yellowstone study suggests volcanic activity is more frequent than previously thought

The Yellowstone super volcano, which basically outlines the whole Yellowstone National Park, is part of one of the most active volcanic regions in the world. A recent research conducted by a joint team of international scientists from Washington State University and the Scottish Universities Environmental Research Centre is set to cast doubts on the frequency of eruptions and, most importantly, super eruptions from the Yellowstone area, which the team found to be more frequent than previously thought.

Yellowstone GeyserYellowstone’s many attractions include geysers, such as Old Faithful, and hot springs, which have been formed, it is believed,  a result of the giant pool of magma that Yellowstone sits on. Beyond its serene and truly beautiful status today, Yellowstone is one of the most dangerous patches on Earth. Its largest eruption took place some 2.1 million years ago, and in the subsequent spew of lava and ash over half of the United States was covered in a dark shroud blocking sun light, and reaching areas of as far away as Texas, Louisiana and southern California, according to the U.S. Geological Survey.

This two-million-year-old lava deposit has three layers.

“That got us thinking whether these things were representing different magma batches [from a single eruption] or different events,” said study leader Ben Ellis, a volcanologist and postdoctoral researcher at Washington State University.

The team lead by Ellis analyzed rock samples from all three layers using the latest isotope dating techniques, involving the potassium 40 and argon 40 isotopes. Like a geological clock, the technique helps dating samples and have a precision of 0.2 percent. Darren Mark, study co-author at the Scottish research center, recently helped fine tune the technique to improve it by 1.2 percent. Apparently, the uppermost layer of lava was deposited some time later than the other two, hinting that a second eruption took place.

The team of researchers claim that the super eruption, which formed  massive volcanic depressions known as “calderas“, most famous of which being Huckleberry Ridge, actually took place in two different eruptions at least 6,000 years apart. The first eruption generated 2,200 cubic kilometers of volcanic material, while the second, smaller eruption generated 290 cubic kilometers. As a measure of comparison, the infamous Mount St. Helens volcanic eruption from 1980 produced about 1 cubic km of volcanic material.

These latest findings, which were reported in a recent paper published in the journal Quaternary Geochronology, suggest that the Yellowstone super eruption are less powerful, and more frequent at the same time than previously thought. Also, the study suggest that the volcanic formation known as the Island Park Caldera is more active than previously thought and could help geologists to more accurately predict its next seismic event. The caldera is actually comprised of two smaller calderas and stretches 58 miles from Wyoming to Idaho. The last known Yellowstone eruption to cause a lava flow was about 70,000 years ago, smaller steam-only eruptions have caused seismic events like the one at Yellowstone Lake almost 14,000 years ago that created a 5 km crater.

source: national geographic 

Katla volcanic eruption

Icelandic volcano eruption might cause local turmoil

For the past few months, the mighty Katla volcano, close to the Icelandic coast, has been exhibiting intense seismic activity, hinting towards an imminent eruption. With a caldera of 10 kilometers, a long history of causing havoc and pain, Katla has the potential of flooding the Atlantic Ocean with billions of gallons of water left over from the melting of its frozen surface, as well as climate change aftermaths.

“There has been a great deal of seismic activity,” says Ford Cochran, National Geographic‘s expert on Iceland.

Just recently, only in the month of October, about 500 tremors were registered around the caldera of Katla, suggesting magma movement and intense seismic activity. On July 9th a small eruption occurred, foretelling of a greater eruption in the near future,  and since then Icelandic scientists have been closely following Katla’s activity.

Katla volcanic eruption

“The 9 July event seems to mark the beginning of a new period of unrest for Katla, the fourth we know in the last half century,” says Professor Pall Einarsson, who has been studying volcanoes for 40 years and works at the Iceland University Institute of Earth Sciences.

“The possibility that it may include a larger eruption cannot be excluded,” he continues. “Katla is a very active and versatile volcano. It has a long history of large eruptions, some of which have caused considerable damage.”

Some short historical milestones from Katla’s havoc wrecking past: in 1918, the last recorded major Katla eruption was so powerful that entire glaciers were swept towards the ocean. In 1755, the volume of water produced by its eruption was equal to that of all the world’s rivers combined. In 1783 volcanoes in the area, not only Katla, erupted continuously for eight months, the results of which would very much resemble the effects of a nuclear winter – ash, hydrogen fluoride and sulfur dioxide clouded the sky. Back then one in five Icelanders were killed, along with half of the country’s entire livestock.

Some of you might remember another recent eruption from Iceland, though not of Katla, but of Eyjafjallajokull. The name might not ring a bell, but you might recall how air traffic around Europe was halted for days; and Eyjafjallajokull is just like a little cousin compared to Katla. Back in 2010, scientists said a Katla eruption could be ten times stronger than the wrath of Eyjafjallajokull and shoot larger and higher plumes of ash, and also result in a tremendous amount of water seeping through Katla’s opening.

Based on previous patterns, that have Katla massively erupting every 40 to 80 years, it seems that the volcano is due. However, one should not threat too hard upon its consequences. A number of media outlets in the past few days have been over-hyping the effects that Katla’s eruption would pose, the most notable of which is the claim of a global impact. Apart, maybe, from some unpleasant groundings of air traffic in Europe, if the wind conditions are unfavorable, there’s little impact farther from its local surroundings that Katla might be able to generate. Still, Iceland will continue to tread on thin ice for the upcoming months. Pun intended.