Tag Archives: volcanic eruption

The Bulge is back: Three Sister volcano in Oregon triggers swelling but is unlikely to erupt

Using satellite images and GPS instruments, geophysicists monitoring the Three Sister volcanoes have found a subtle but noticeable uplift around 3 miles (5 km) away from the South Sister volcano. While researchers are now keeping a closer eye on it, they say this type of uplift has happened before and there’s no need to worry.

Image credits: USGS.

The Three Sisters are closely spaced volcanic peaks in Oregon, USA. They stand over 10,000 feet (3,000 m) in elevation, being the 4th, 5th, and 6th highest peaks in Oregon, respectively. But researchers are more interested in their volcanic activity.

While the North and Middle sisters haven’t erupted in the past 14,000 years (and it’s considered unlikely that they will erupt again), the South Sister last erupted 2,000 years ago, and could easily do so again at some point in the not-very-distant future. In the 1990s, researchers detected tectonic uplift around this volcano, prompting the United States Geological Survey (USGS) to closely monitor the area.

The USGS is now tracking developments around the South Sister using GPS networks and satellite data. Radar satellites can highlight areas of uplifting (where the surface is bulging) or downwelling (where the surface is moving downwards). Then, ground-based GPS measurements are used for more precise measurements. Although the current uplifting isn’t as fast as the maximum rate observed in 1999-2000, it is “distinctly faster” than the normal rate of uplift, the USGS says.

Image credits: USGS.

The uplift is believed to be caused by pulses of magma accumulating under the volcano, some 4 miles (7 km) below the surface. While magma accumulation is associated with volcanic activity, eruptions are generally preceded by other detectable signs — most importantly, lots of small earthquakes, but also ground deformation and geochemical changes. There seems to be no sign of any of that around the Three Sisters.

All in all, this suggests that the volcano is still active, but there are no signs of an impending eruption. The volcano’s alert level and color code remain at Normal / Green.

How the USGS is tracking activity around the Three Sisters. Credit: USGS.

The Three Sisters volcanoes formed in the Pleistocene and belonged to a volcanic area that was very active from around 650,000 and about 250,000 years ago. The South Sister is the youngest and tallest of the three volcanoes, and unlike its sisters, it has an uneroded summit crater about 0.25 mi (0.40 km), which hosts a lake (called the Teardrop Pool).

An eruption from the South Sister would pose a significant threat to nearby life, with geologists estimating a proximal zone of danger extending from 1.2 to 6.2 miles (2-10 km) around the volcano summit. How flows would run down the sides of the volcano, threatening everything in its path, and the nearby city of bends would be covered by tephra some 2 inches (5 cm) thick.

The Teardrop Pool on South Sister is the highest lake in Oregon. Image via Wiki Commons.

Little-known 2012 volcanic eruption was actually the largest in over a century, new data shows

In July 2012, geologists noted the eruption of a previously little-known volcanic area called Havre Seamount, located off the coast of New Zealand. Now, after analyzing the data more thoroughly, they say it was one of the largest eruptions in modern history — we just didn’t realize it because it took place underwater.

An echosounder image showing the undersea volcano called Havre Seamount, including a new cone that formed during the July 2012 eruption. Credit: NIWA/GNS Science.

The eruption of the Havre Seamount was not initially noticed by scientists. Havre Seamount was only discovered in 2002, and researchers weren’t even aware that the area was volcanic. But as it erupted, it offered passengers on an airline flight over the Southwest Pacific an unusual display: a raft of porous, floating rock (known as pumice), as big as 150 square miles — that’s 50% bigger than the surface of Paris.

Maggie de Grau was a passenger on that flight. Like many others on that plane, she took photos of the strange phenomenon, which she proceeded to email to Dr. Scott Bryan, a senior research fellow at Queensland University of Technology. The raft grew even more, and Bryan contacted some of his colleagues, ultimately discovering that a few military pilots had also witnessed the event days and weeks after the eruption. An officer in the Royal Australian Navy was quoted as saying that it was “the weirdest thing [he had] seen in 18 years at sea.” It was at that point that scientists knew they had something much bigger on their hands.

“We knew it was a large-scale eruption, approximately equivalent to the biggest eruption we’ve seen on land in the 20th Century,” said Rebecca Carey, a volcanologist at University of Tasmania and Co-Chief Scientist on the expedition.

NASA image of Havre Seamount eruption and initial formation of pumice raft.

After the pumice raft was detected, the gears started to turn. Seismologists quickly pinpointed and described a cluster of earthquakes consistent with magma rising into a magma chamber prior to eruption. Retrospective analysis of satellite imagery also revealed the pumice, and so, a mission to map the seafloor topography and monitor any changes was launched in 2015.

Using a pair of autonomous underwater vehicles, they were able to dive beneath the surface of the water and see what neither the earthquakes nor the satellite imagery could reveal: what the eruption looked like. Now, these results have finally been published.

“When we used the submersible vehicles to go down to the seafloor in 2015, we were able to see a vast array of new volcanic products, such as 14 different lava flows at depths of between 1,220 and 650 metres beneath sea level,” says Rebecca Carey, lead researcher on the study, which has been published in the journal Science Advances.

High-resolution seafloor topography of the Havre caldera mapped by the autonomous underwater vehicle (AUV) Sentry shows the lava that erupted in 2012 in red. The volcano is nearly a mile deep (1,519 meters). The top of the volcano is at 650 meters below sea level. Credit: Rebecca Carey, University of Tasmania, Adam Soule, WHOI/

As it turns out, the Havre eruption has some intriguing particularities. For starters, it’s the largest deep-ocean eruption in recorded history and one of very few recorded submarine eruptions involving rhyolite magma — a type of silica-rich magma. Eruptions involving this type of magma are violent and explosive, but most of what we know about them comes from rock records. Scientists have never before been able to analyze such an eruption shortly after it occurred.

The eruption was also more complex — it’s not just one volcano cone that erupted. It consisted of lava from 14 volcanic vent sites between 900 and 1220 meters (3000 and 4000 feet) below the surface. The sheer size of the eruption was also impressive: 1.5 times larger than the 1980 eruption of Mount St. Helens. But unlike that eruption, this one didn’t produce an explosive tower due to water pressure. The water pushing down on the lava suppressed most of the explosivity we would have seen if the eruption had taken place on land. However, rather interestingly, lava flows look exactly like how they would if they were on land; but unlike a land eruption, 75 percent of the lava floated to the surface and drifted away with the currents.

 

 

Images of ship-based mapping compared with autonomous vehicle mapping. Credits: University of Tasmania, Australia.

It’s not surprising at all that geologists didn’t grasp the full scale of this eruption at first. More than 70 percent of the planet’s volcanic activity happens underwater, but the details are often hidden to us. Getting the chance to explore this eruption hands on is a rare opportunity.

However, while for geologists this is a thrilling discovery, wildlife may have been greatly affected by the scale of the eruption. Carey says biologists are “very interested to learn more about how species recolonise, and where those new species are coming from”. All in all, they brought back a trove of data which will take years to analyze. It will take a long time before we finally grasp the ramifications of the 2012 Havre eruption.

“There is a decade worth of interdisciplinary science to do based on our 2015 voyage data and samples. It’s very exciting to marry the geosciences with other scientific disciplines addressing novel research questions,” concludes Carey

Journal Reference: Rebecca Carey et al. The largest deep-ocean silicic volcanic eruption of the past century.

Warm rock beneath New England hints of upcoming volcanic eruption millions of years from now

This magma eruption could happen in some parts of New England, but not in the next couple million years. Credit: Pixabay.

This lava eruption could happen in some parts of New England, but not in the next couple million years. Credit: Pixabay.

Geologists have identified a “mass of warm rock” that is rising beneath northern New England. The formation could be an ominous sign of a possible volcanic eruption millions of years from now.

“The upwelling we detected is like a hot air balloon, and we infer that something is rising up through the deeper part of our planet under New England,” said lead author Vadim Levin, a geophysicist at Rutgers University. “It is not Yellowstone (National Park)-like, but it’s a distant relative in the sense that something relatively small – no more than a couple hundred miles across – is happening.”

“Our study challenges the established notion of how the continents on which we live behave,” Levin said. “It challenges the textbook concepts taught in introductory geology classes.”

Levin and colleagues tapped into the EarthScope program which employs thousands of seismometers, each spaced 46.6 miles apart, covering the continental United States. The scale of the program, whose mission is to reveal the structure and evolution of the North American continent, is unprecedented.

Credit: A colored map of mantle flow under the North American tectonic plate. The warm colors indicate lower speed, implying that rock in those regions is less dense, likely warmer and rising toward the surface. Credit: Vadim Levin/Rutgers University-New Brunswick.

By studying seismic waves recorded over the last two years, the Rutgers researchers could peer inside Earth’s interior, where they could see the shapes and texture of structures but also changes in the state of materials. Levin’s team focused their study on the New England area because that’s where an anomalous area of great warmth in the upper mantle was previously reported.

Following a careful assessment of this area of interest, the researchers detected an upwelling pattern beneath central Vermont and western New Hampshire but also parts of western Massachusetts. In this region, mantle flow indicators are the smallest, likely because warmer rock flows upward and disrupts the horizontal flow. Given enough time, the magma could erupt to the surface.

New England residents shouldn’t be too worried that a volcano will suddenly pop up in their backyards. Such an event looks to be millions of years away.

“The Atlantic margin of North America did not experience intense geologic activity for nearly 200 million years,” Levin said. “It is now a so-called ‘passive margin’ – a region where slow loss of heat within the Earth and erosion by wind and water on the surface are the primary change agents. So we did not expect to find abrupt changes in physical properties beneath this region, and the likely explanation points to a much more dynamic regime underneath this old, geologically quiet area.”

“It will likely take millions of years for the upwelling to get where it’s going,” he added. “The next step is to try to understand how exactly it’s happening.”

Findings were reported in the journal Geology

 

The Permian extinction – caused by “lemon juice” acidic rain ?

  • The Permian extinction was the biggest extinction ever, killing 96% of all marine species and 70% of terrestrial vertebrates
  • Possible causes include: impact, loss of oxygen and volcanic eruptions
  • Researchers tested the validity of the last hypothesis, finding it likely

The biggest extinction – ever

Artistic representation of the Permian plants, affected by acidic rain. Via MIT.

Artistic representation of the Permian plants, affected by acidic rain. Via MIT.

MIT Researchers believe that rain as acidic as undiluted lemon juice may have contributed to massive extinction that took place at the end of the Permian, 252 million years ago. These acidic rains may have played a part in killing off plants and organisms around the world during what is regarded as the most severe extinction the world has ever gone through.

It was so severe that it killed 96% of all marine species and 70% of terrestrial vertebrate species – and it took life about 10 million years to recover from it!

Pin-pointing the exact cause (or causes) of the Permian–Triassic extinction event is a difficult undertaking because it took place so long ago that most of the evidence was destroyed, eroded or buried away. There’s a major scientific debate, centering on several potential causes:

– an asteroid impact, similar to what wiped off the dinosaurs at the end of the Mesozoic
– a gradual, global loss of oxygen in the oceans
– a host of environmental changes caused by massive volcanic eruptions in today’s Siberia.

Now, researchers at MIT have simulated the final possibility. They created a climate model for a Permian world in which massive eruptions took place, ejecting volcanic gases (including sulfur) into the atmosphere. They found that if this were the case, then sulfur emissions were significant enough to create widespread acid rain throughout the Northern Hemisphere, with pH levels reaching 2 — as acidic as undiluted lemon juice. These acidic rains alone would have been enough to maim virtually all living plants, halting their growth and development, ultimately leading to the massive extinction.

“Imagine you’re a plant that’s growing happily in the latest Permian,” says Benjamin Black, a postdoc in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “It’s been getting hotter and hotter, but perhaps your species has had time to adjust to that. But then quite suddenly, over the course of a few months, the rain begins to sizzle with sulfuric acid. It would be quite a shock if you were that plant.”

Volcanoes in Siberia

The world at the time of the Permian extinction. Highlighted are the biggest igneous provinces - notice Siberia.

The world at the time of the Permian extinction. Highlighted are the biggest igneous provinces – notice Siberia. Source

It’s hard to wrap your mind around such a dramatic event as this one, and in a way, it’s hard to believe that it was just a single cause – it seems pretty likely that at least a couple of separate, unfortunate elements converged towards this extinction. Geologists analyzing the rocks in Siberia found evidence of immense volcanism that came in short bursts beginning near the end of the Permian period and continuing for another million years. The volume of the magma was several million cubic kilometers, enough to put a thick cover over all the United States. But even so, were these eruptions enough on their own?

The group simulated 27 scenarios, each approximating the release of gases from a plausible volcanic episode, including a wide range of gases in their simulations, based on estimates from chemical analyses and thermal modeling. They then modeled the interaction between these gases and the atmosphere, ultimately, how they were absorbed and then came down as low pH rain.

They found that with repeated bursts of volcanic activity, the acidic rains had a dramatic effect on land plants, probably going way past the point they could handle.

“Plants and animals wouldn’t have much time to adapt to these changes in the pH of rain,” Black says. “I think it certainly contributed to the environmental stress which was making it difficult for plants and animals to survive. At a certain point you have to ask, ‘How much can a plant take?’”

Now, Black hopes paleontologists and geochemists will consider his own results and compare them with their own observations of the Permian extinction, in order to paint a more accurate picture.

“It’s not just one thing that was unpleasant,” Black says. “It’s this whole host of really nasty atmospheric and environmental effects. These results really made me feel sorry for end-Permian organisms.”

Study puts growth of Hawaiian volcanoes in a different perspective

Even an area so studied as Hawaii sometimes yields surprises – a recent study conducted by researchers at the University of Hawaiʻi at Mānoa School of Ocean and Earth Science and Technology (SOEST) and the University of Rhode Island (URI) changes the very foundation of how the Hawaii islands were formed: it is the eruptions of lava on the surface, extrusion, which grow Hawaiian volcanoes, rather than internal emplacement of magma, as was previously thought.

3-D view of topography & seafloor relief of Hawaiian Islands; colors show residual gravity anomaly - red shows higher densities, blue shows lower densities.

3-D view of topography & seafloor relief of Hawaiian Islands; colors show residual gravity anomaly – red shows higher densities, blue shows lower densities.

Before this, the currently accepted theory was that Hawaiian volcanoes grew primarily internally – magma intrudes and solidifies before it hits the surface. While this type of growth does occur, it is definitely not the major component of the growth; previous studies which concluded otherwise were based on observations over a very small time frame.

“The discrepancy we see between our estimate and these past estimates emphasizes that the short-term processes we currently see in Hawaiʻi (which tend to be more intrusive) do not represent the predominant character of their volcanic activity,” said Ashton Flinders, study author.

Ashton Flinders (M.S. from UHM), lead author and graduate student at URI worked with his colleagues and Jim Kauhikaua of the U.S. Geological Survey – Hawaiʻi Volcano Observatory to compile historical land-based gravity surveys as well as marine surveys from the National Geophysical Data Center and from the UH R/V Kilo Moana. These data provide an insight over longer periods of time.

This could have a significant impact on how the island develops and what kind of challenges it has to face in the future.

“This could imply that over the long-term, Kilauea’s ERZ will see less seismic activity and more eruptive activity that previously thought. The 3-decade-old eruption along Kilauea’s ERZ [east rift zone] could last for many, many more decades to come,” said Dr. Garrett Ito, Professor of Geology and Geophysics at UHM and co-author.

“I think one of the more interesting possible implications is how the intrusive-to-extrusive ratio impacts the stability of the volcano’s flank. Collapses occur over a range of scales from as large as the whole flank of a volcano, to bench collapses on the south coast of Big Island, to small rock falls,” said Flinders. Intrusive magma is more dense and structurally stronger than lava flows. “If the bulk of the islands are made from these weak extrusive flows then this would account for some of the collapses that have been documented, but this is mainly just speculation as of now.”

They are now working on a new density model which will serve as a starting point for future studies and pave the way for a better understanding of the entire volcanic system.

Via University of Hawai’i at Manoa.

Oil spills could offer valuable information in modelling volcanic eruptions

What do volcanic eruptions, oil spills, sewages and chimneys all have in common? Not much at a first glance – but if you ask Peter Baines, a scientist at the University of Melbourne in Australia, they are tightly connected; in all these events, a fluid rises into a environment stratified by density (like the atmosphere or the ocean).

Example of aquatic stratification

Example of aquatic stratification

It’s not the first time scientist attempt to model these events (intrusions), but it is the first time a new element is added – the crossflow caused by winds and currents. Banes thought the most useful application of his work is estimating how much ash will pour out of a volcano, and how much oil will gush as a result of a spill. Baines is now working with volcanologists in Britain to apply his model to historic eruptions and see if it adds up. He focused on the Late Campanian Event and the Toba supereruption that occurred around 73,000 years ago in Indonesia. Using information derived from sedimentary deposits of ash and tuff, geologists are trying to estimate the amount and speed of ejected material, and see if it fits with what Baines ‘predicted’.

“Most of what we know about prehistoric eruptions is from sedimentary records,” said Baines. “You then have to try to infer what the nature of the eruption was, when this is the only information you’ve got.”

To understand how intrusions work in a stratified environment in the presence of crossflows Baines developed what he calls a semi-analytical model: he did begin with standard fluid dynamics equations, but then he used numerical calculations to approximate solutions for specific combinations of source flow, spread rates, crossroad speed and direction – he reached quite an interesting conclusion: under normal wind speeds, the intruding fluid reached a maximum thickness at a certain distance upstream from the source, and thinned in the downstream direction. The distance to the upstream stagnation point depended much more on the rate of source flow than the crossflow speed. Now, it remains to be seen if this theoretical model will pass the practice test.

Volcano screams may explain unusually powerful explosion

Lots of volcanoes erupted in 2009 – but one of them really screamed out. Its unique howls provide a glimpse into the very heart of the volcano, and also in some unexplained processes that accompany an eruption.

redoubt

Credit: Chris Waythomas, Alaska Volcano Observatory

It’s not unusual for swarms of small earthquakes to precede a volcanic eruption – it’s quite common. As a matter of fact, most volcano alerts rely on seismic monitoring. However, sometimes, these earthquakes follow each other so fast that they create a signal called harmonic tremor that resembles sound made by various types of musical instruments – though at much lower frequencies than the ones our ears can pick up.

When the Redoubt Volcano in Alaska started erupting in 2009, local seismic stations detected a flurry of tiny tremors of magnitude 0.5 to 1.5. However, in the final minute before the eruption, the earthquake frequency peaked at 30 events / second, which means that all of them merged into a flurry of temblors. A new analysis of those events showed that the harmonic tremor glided to substantially higher frequencies and then stopped abruptly just before six of the eruptions.

“The frequency of this tremor is unusually high for a volcano, and it’s not easily explained by many of the accepted theories,” said Alicia Hotovec-Ellis, a University of Washington doctoral student in Earth and space sciences.

Seismologists working on the case have dubbed the stream “the seismic scream”, because it built to a crescendo of increasing pitch. They hope that by studying this phenomenon, they will get more insight into the pressure changes which take place inside a volcano before the eruption, refining models and provoding a better understanding of the processes ocurring during eruptive cycles in volcanoes like Redoubt, she said.

If you could somehow stand in the magma (or even better, swim in it), you’d hear the “screams” as a loud continuous rumbling. But if you were standing on the top of the volcano, by the time the sound reaches you it would be very dampened, up to the point where you’d just hear a vague hum, says Eric Dunham at Stanford University in California, who is part of the team analysing the vibrations.

redoubt2

The team has developed a mathematical model of the seismic activity; the model shows a pressure build-up which increases the friction between the magma and the volcano walls, causing them to slip by each other more and more violently, creating the small earthquakes seismologists observed. Each one of these frictions results in a small earthquake. But the good thing is that this doesn’t lead to a big temblor.

“Because there’s less time between each earthquake, there’s not enough time to build up enough pressure for a bigger one,” Hotovec-Ellis said. “After the frequency glides up to a ridiculously high frequency, it pauses and then it explodes.”

So far, the description of this phenomena is unique to the world of geology, but the odds are that this is not a unique case – just a very clear one.

“Redoubt is unique in that it is much clearer that that is what’s going on,” Hotovec-Ellis said. “I think the next step is understanding why the stresses are so high.”

Scientific article

Alaska volcano as seen from outer space

Image via NASA.

The Pavlof volcano lies in the long chain of the Aleutian Islands off the west coast of Alaska, and is one of the most active volcanoes in the United States. It’s about seven kilometers (4 miles) across and 2500 meters (1.5 miles) high; after being quiet since 2007, it started erupting again in May 2013.

The ash cloud went as high as 320 km into the atmosphere, which gave the guys on the International Space Station to take some stunning orbital pictures of the eruption.

Even though the eruption itself wasn’t that dangerous, the volcanic ash can be a hazard; it’s not made from smooth, rounded particles, but rather have extremely sharp edges which can easily choke airplane engine and damage windshields.

‘It’s dangerous for the people downwind of it, because you don’t really want to breathe in that fine ash that long,’ Wessels said of the eruption taking place on the Alaska Peninsula, 590 miles (950km) southwest of Anchorage.

The thing is, images of volcanoes taken from outer space, as awesome as it sounds, are not that cool. However, astronauts from the ISS have much more flexibility than your average satellite, and they can capture such an event from multiple angles.

These pictures for example, were taken with a Nikon D3S digital camera equipped with an 800, 400, and 50 millimeter lens, respectively.

 

NASA researchers use unmanned planes to trace toxic vulcanic gas

Usually, the military taps into what science does and uses its technologies – but for once, it was the other way around. Using unmannes planes typically designed for city warfare, scientists were able to keep track of toxic volcanic fumes.

turrialba volcano

The Dragon Eye remote-controlled plane weighs in at just under 6 pounds (2.7 kilograms), with a 3.75-foot (1.14 meters) wingspan and 2 electric motors. Designed for the military, it is commonly used for reconnaisance; showing some good practical sense, NASA acquired three retired Dragon Eye planes and sent them to Costa Rica to monitor Turrialba Volcano. The volcano is especially well known for ongoing sulphur dioxide emissions, which are very harmful to crops and humans directly.

The project’s goal is to take a more detailed look at the direction of volcanic plumes, and the concentration and distribution of volcanic gases than is possible with satellites.

“It is very difficult to gather data from within volcanic eruption columns and plumes because updraft wind speeds are very high and high ash concentrations can quickly destroy aircraft engines,” David Pieri, the project’s principal investigator and a research scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. “Such flight environments can be very dangerous to manned aircraft.”

The planes just carried a 1-pound (0.5 kg) sensor payload above the volcano’s summit, with flights ranging as high as 12,500 feet (3,810 m) above sea level, and the results were very satisfying. In the future, NASA wants to bring an ever bigger plane, which can carry a heavier sensor, to detect other potentially harmful gases emitted by the volcano.

Geologists grant full access to details of every significant recorded volcanic eruption

Details of some 2000 volcanic eruptions that occurred in the past 1.8 million years are now available in a new open access database, complied by scientists at the University of Bristol with help from the UK, US, Colombia and Japan.

The Paluweh volcano; copyright Tom Pfeiffer.

The Paluweh volcano; copyright Tom Pfeiffer.

Volcanic eruptions are among the most dangerous natural hazards, having the potential to take numerous lives, significantly impact climate, disrupt air traffic and dramatically alter the surrounding landscapes. Knowledge of past behaviors is often the best way to be prepared for future events – this is what led Dr Sian Crosweller from the Bristol’s School of Earth Sciences to head a team which created the database. The open access database of Large Magnitude Explosive Eruptions (LaMEVE) will provide this crucial information to researchers, civil authorities and the general public alike.

“Magnitude 4 or greater eruptions – such as Vesuvius in 79AD, Krakatoa in 1883 and Mount St Helens in 1980 – are typically responsible for the most loss of life in the historical period. The database’s restriction to eruptions of this size puts the emphasis on events whose low frequency and large hazard footprint mean preparation and response are often poor.”, explained Dr. Crosweller.

Currently, the data includes magnitude, Volcanic Explosivity Index (VEI), deposit volumes, eruption dates, and rock type – the main parameters for describing a volcanic eruption. However, more data will probably be added, especially for the major events. The most important expansion planned for LaMEVE is inclusion of the principal volcanic hazards (such as pyroclastic flows, tephra fall, lahars, debris avalanches, ballistics), and vulnerability (for example, population figures, building type) – details mostly centered around the areas at risk.

Principal Investigator and co-author, Professor Stephen Sparks of Bristol’s School of Earth Sciences said:

“The long-term goal of this project is to have a global source of freely available information on volcanic hazards that can be used to develop protocols in the event of volcanic eruptions. Importantly, the scientific community are invited to actively participate with the database by sending new data and modifications to the database manager and, after being given clearance as a GVM user, entering data thereby maintaining the resource’s dynamism and relevance.”

LaMEVE is publicly available for anyone here. The research paper was published in the Journal of Applied Volcanology, and for more information you can go here.

Mount Ruapehu is the highest mountain on the North Island.

Mount Doom from LOTR set to erupt – in real life

Mount Ruapehu is the highest mountain on the North Island.

Mount Ruapehu is the highest mountain on the North Island.

For his fantastic Lord of the Rings trilogy, director Peter Jackson relied on two volcanoes in New Zealand, Mount Ngauruhoe and Mount Ruapehu, to portray Mount Doom. The latter, however, is keen on showing that it can be bad off-screen as well, after geologists warn that it’s nearing an impending eruption.

“The current situation can’t continue, Ruapehu is so active that the temperatures have been going up and down a lot,” DOC volcanic risk manager Harry Keys told Radio New Zealand.
“They generally haven’t gone up as we’ve expected for some weeks now and sooner or later that situation will be rectified, either in a small, relatively passive way, or with a significant eruption.”

Temperature measurements from a few hundred meters below the lake that sits in the mountain’s crater range at around 800 degrees Celsius (1,472 Fahrenheit), however the water temperature of the lake itself lies only at 20 degrees Celsius. This is a clear sign, according to geologists, that a vent was partially blocked, leading to increased pressure that made eruptions more likely “over the next weeks to months”.

The Department of Conservation (DOC) warns tourists not to stray too close to Ruapehu. The biggest concern, as with all volcanic eruptions, lies with lahar — an avalanche-like wave of ash, mud, gravel and debris, triggered by volcanic activity. Ruapehu’s last eruption was in 2007, when a steaming lahar rushed down hill, causing no injuries fortunately. In 1953, however a massive lahar from the mountain caused New Zealand’s worst rail disaster when it washed away a bridge at Tangiwai and a passenger train plunged into the Whangaehu River, claiming 151 lives.

source

Volcanic crystals might predict next big eruption

Analysis of crystal formed in the molten rocks of a volcano might predict volcanic eruptions with as much as a year in advance, researchers claim.

Mixing Seismology and Petrology

Different types of seismic recording; volcanic eruptions cause harmonic tremors, different from any other ones. Via USGS

Drawing data from the volcanic activity of Mount Helens from 1980 through 1986, geologists found that iron- and magnesium-rich crystals grow before an eruption, and by far, the most rapid growth of such crystals took place 12 months before an eruption.

Most active volcanoes, before erupting, display specific patterns of seismicity; monitoring these events, as well as, ground deformations, gas emissions and changes in water level are the best thing we have so far in terms of predicting volcanic eruptions. However, while these methods provide good indications, such a technique, if perfected, would dramatically improve the odds of predicting such an event.

“Volcanoes tend to erupt in a similar cycle and have similar trends,” said Kate Saunders, a study author and geologist at the University of Bristol in England, in a telephone interview. “If we can work out their behavior, it allows us to know what to look for. We can better evaluate the monitoring signals.”

Analyzing igneous rocks

Igneous rocks are one of the three major types of rocks (along with sedimentary and metamorphic), formed through the cooling and solidification of magma. When these rocks cool slowly, below the surface, they form visible, specific, crystals. Among the minerals form through this process are orthpyroxenes, silicate minerals comprising of single chains of chemical tetrahedra.

Dr Saunders and colleagues studied zoned crystals of orthpyroxenes, which grow concentrically like tree rings within the magma body. What happens is that these zones have slightly different chemical compositions, reflecting physical and chemical changes in the magmatic chamber where they were formed, thus giving a good indication of volcanic processes and the geological time setting when they occur, much like the rings on a tree.

Forensic mineralogy

Zoned orthopyroxene - not with its real color. The colors show the zones with different chemistries

Researchers used a technique called diffusion chronometry applied to orthopyroxene crystal rims, showing that episodes of magma intrusion correlate temporally with recorded seismicity, providing evidence that some seismic events are related to magma intrusion. Diffusion chronometry works in an almost forensic fashion, and it can must be applied to more volcanoes, in order to verify if this feature is present in all volcanoes, or if this was just a unlikely chance. If it isn’t then researchers have just struck gold.

“Such a correlation between crystal growth and volcanic seismicity has been long anticipated, but to see such clear evidence of this relationship is remarkable.”, explained Dr. Saunders.

Source

A busy year for Etna continues wth 17th eruption

We still have a few months to go in this year, and Etna still doesn’t look like it wants to stop its activity. The stratovolcano located in Sicily has already had its 17th eruption, whichm unlike most this year, came as quite a surprise.

Photo by gnuckx from an eruption in January.

The volcano provided no seismic clues, instead the crater just filling up with lava and pushing it forward, in a dazzling display of light and smoke. Since it seems Etna has made it quite a habbit to erupt at night, we have some great pictures of the event.You can also see a video of the eruption here; the lava fountaning from the top of the crater to the slopes of the mountain is fascinating if you ask me.

Mount Etna intensifies eruption

Italy’s Mount Etna is intensifying its eruption, shooting up more lava and ash in the air.

Italy’s Civil Protection agency says that they have received raports from the geophysics and volcanology institute on Monday, announcing the increase in volume of ejected material, eight days after the initial eruption began.

Local authorities state that Etna started spewing out a significant amount of ash in a southeast direction early in the day but the eruption only lasted for about two hours, than it slowly stopped. However, this is extremely dangerous because the volcano has several inhabitated villages located right on its slopes, not very far away from the crater. Even though eruptions are not that uncommon in the area, people continue to inhabit the volcanic mountain.

Located in Sicily, mount Etna is an active volcano, the tallest one in Europe, at 3,329 metres above sea level (varying slightly during eruptions). It is a stratovolcano, which means it is characterized by a steep profile and periodic, explosive eruptions – one of the most active volcanoes in the world.

Spledid photos from the Sakurajima volcano eruption

Sakurajima is probably the most active and dangerous volcano in Japan. Actually, one of its eruptions from back in 1914 is still attested as the the most powerful volcanic eruption in Japanese history, which at the time engulfed a whole city in ash and lava, and joined the former island with the neighboring Osumi Peninsula.

Photo by Kimon Berlin.

Curious to find more about Sakurajima, in came instead across some incredible photographs taken by alien landscape photographer Martin Rietze, who managed to capture Sakurajima in its full elemental splendor. I’m still left short of words after glaring through them for the past hour now, so I’ll just leave you with these beauts right below. As a small notice, the lightning you see next or through the lava is by no meas a Photoshop effect. What actually happens is that fast moving fine ash causes the flashing lightining – the more plume there is, the more intense the lightning gets. For a conclusive example check out this photo of last year’s eruption from Shinmoedake peak.

 

 

 

 

 

 

 

 

 

The big picture on Icelandic eruption

Eyjafjallajökull (how ever you pronounce) is a volcano located in Iceland, covered by a small glacier with the same name. It’s crater has a diameter of about 3-4 kilometers, and it erupted the second time this month, causing a cloud of ash that forced authorities to stop almost all flights above Iceland.

The first fissure that opened on Fimmvörðuháls, as seen from Austurgígar. Photo by David Karnå.

The first fissure that opened on Fimmvörðuháls, as seen from Austurgígar. Photo by David Karnå.

The problem, when you have such a volcano, is that the ice on top of it melts, causing massive floods, as well as the usual shooting of smoke and gases. Thousands of people were forced to give up their homes and take cover in the face of the floods. Here we’ll present some of the most suggestive photos from the area, taken over a time span of approximately a month.

Photo by NASA.

Photo by NASA.

 

6 deadliest volcano eruptions

Volcanic eruptions are impressive natural phenomena; it begins when pressure on a magma chamber forces magma up through the conduit and out the volcano’s vents. Seen on the TV or in the newspaper, they’re just fantastic and gorgeous. But if you’re unlucky enough to be there… it’s really deadly. But volcanic ash can also bring a new beginning, aiding nature to grow even bigger and stronger than before. But the lives lost are forever gone. Here’s a sum of the world’s 6 deadliest volcano eruptions, in terms of human live loss – for both direct and indirect causes.

6. Laki, Iceland; year: 1783; 9,350 deaths, caused mostly by starvation

laki

5. Unzen, Japan; year: 1792; 14,300 deaths, caused mostly by the volcano collapsing.

unzen

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