Google Street View Takes You Inside An Active Volcano

IBT
HIMANSHU GOENKA @HIMGOJOURNO

 03/16/17 AT 2:26 AM

The lava lake inside Marum crater on Ambrym island, Vanuatu, can be seen in this Google Maps image. Photo: Google


In the newest offering from its Maps stables, Google announced Wednesday that its Street View feature now offers a literally breathtaking view of one of the world’s largest lava lakes. You can now, with a click, explore the Marum crater on Ambrym island in the Pacific, one of the nine active volcanoes in the island nation of Vanuatu.

“To get inside the active volcano, we partnered with explorers Geoff Mackley and Chris Horsley, who repelled 400 meters into the Marum crater with a Street View Trekker collecting 360-degree imagery of the journey down to the molten lava lake, which is roughly the size of two football fields,” Google said in a blog post.

A Close-up of the lava lake inside the Marum crater, an active volcano on Ambrym island, Vanuatu. Photo: Google

Speaking about the experience, Mackley said in the post: “You only realize how insignificant humans are when you’re standing next to a giant lake of fiery boiling rock.”

Co-explorer Horsley said after climbing back up: “Standing at the edge and feeling the heat lick your skin is phenomenal. I hope that by putting this place on the map people will realize what a beautiful world we live in.”

You can explore the Street View of the Marum crater using this link.

Ambrym is home to another active volcano called Benbow, which sits — along with Marum — in the same 39-square-mile volcanic caldera. About 7,000 people also live on the island and one of the villages, Endu, has also been mapped as part of the Google project.

The village of Endu, in the foothills of the volcanic peaks of Ambrym island, Vanuatu. Photo: Google

Chief Moses of the village said the locals believe the two volcanoes to be devils, Benbow the husband and Marum the wife, which erupt when they are angry. The village can be explored using this link.

The bangs, crackles and hums of Earth's seismic orchestra

theguardian

Dr. Stephen Hicks

March 16, 2017

Study gets to the bottom of ‘musical symphony’ produced in regions prone to mega-quakes as scientists work toward better quake hazard forecasting




You are at a classical music concert. There is an orchestra with three main sections. High up at the back, the percussion section has one very loud, large and moody-looking drum that gets struck very rarely. A handful of triangles produce occasional quieter “tings”. Further down, in the middle, there is a small band of violinists, but they are playing the strings so slowly the audience can barely hear them. Down at the front, a family of double bass instruments produces low-pitched, gentler hums from time to time.

This somewhat unconventional orchestra is like a type of tectonic plate boundary known as a subduction zone. Subduction zones delineate the battle lines between the collision of two titanic tectonic plates. Yet, this encounter is rather one-sided. One plate firmly stands its ground; the other sinks into the depths of the Earth. The grinding and sliding of these two plates produces a musical concert that can be detected by sensitive geophysical instruments and by humans during large quakes. The shallow parts of subduction plate boundaries can produce devastating mega-earthquakes with magnitude eight or greater (like the giant drum in the percussion section). In the tens to hundreds of years between these massive quakes, scientists eagerly listen to the signals at subduction zones to estimate whether the plate boundary fault is primed for a future quake, and to forecast what a rupture may look like.

At the turn of the century, scientists discovered a new type of “sound” produced at subduction zones, known as Episodic Tremor and Slip(or ETS for short). ETS are typically low-pitched rumbling signals (like the double bass instruments) lasting minutes to hours that do not produce the jolts associated with normal earthquakes. These rumbles come from a type of event known as seismic tremor, which is similar to tiny earthquakes. Moreover, in subduction zones in southwest Japan, Mexico and New Zealand, the gap between the part of the fault that hosts large earthquakes and the zone of ETS is filled with an area producing silent ruptures that occur over many months (the virtually inaudible violinists). These cannot be detected using traditional seismometers.

Regions of the plate boundary that produce tremor and slow slip events are of vital interest. They have been used to delineate the total area of fault (and therefore maximum magnitude) that could rupture in a future mega-quake. Until now, the forces driving the zones of deep tremor and slow slip remained unclear.

In a new study using numerical models that re-create the temperature and deformation conditions deep inside a subduction zone, Dr Kelin Wang and Dr Xiang Gao were able to match observations and infer the main factors that control the depth at which seismic rupture, tremor and slow slip occurs. As oceanic plates sink, they transport huge amounts of water into the deep earth – hundreds of metric tons of water every million years. The presence of water causes rocks and their minerals to change their state and behaviour. One such process produces hydrous minerals, such as serpentine, in the mantle, which in turn reduces the number of pathways for fluid to escape. The ponding of highly pressurised water locally reduces the friction of the fault, causing seismic tremor where the subducting plate meets the mantle of the non-subducting (overlying) plate. The transition to this deep portion of the fault with lower friction therefore causes a domino effect of inducing a part-frictional regime that allows slow-slip events to occur at shallower depths.

Wang, who is based at the Geological Survey of Canada, is one of the lead authors on the study. He says, “this new work brings together very different disciplines of research. We seemed to get stuck in understanding the physical mechanisms of ETS for some time, mainly because we tended to examine one aspect of the complex matter at a time. By integrating different observations and theories, the complex matter became simple”.

The study concludes that the presence of a gap between zones of the fault that are frictionally locked and those which produce ETS means that tremor events cannot rapidly transfer stress to the locked portion. Wang says, “I think the work serves to remind researchers that we cannot readily use slow slip events as precursors of large earthquakes. The relationship between slow slip events and large earthquakes is not as simple as in popular idealized cartoon illustrations”.

However, the authors do not rule out that over time, the cumulative piling up of tremor and slow-slip events could gradually push the locked zone closer toward failure, potentially causing a large and damaging rupture. Fortunately, scientific organisations in many regions, such as in Japan and the Cascadia subduction regions continue to keep a close eye on ETS events. Dense on-land and sea-floor networks of geophysical monitoring instruments able to detect any potential movement of tremor and slow slip toward the locked and primed portion of the plate boundary fault. ■

Scientists have finally figured out what caused the largest volcanic eruption in human history

Lindsay Dodgson

Business Insider UK

Jan 27, 2017

A satellite image of Lake Toba in Indonesia. NASA Landsat


Indonesian volcano Toba produced a cataclysmic eruption that devastated the region 73,000 years ago. Monstrous volcanoes like this are called supervolcanoes, and sometimes their impacts are so huge, they can cause global climate change.

Now, scientists may have worked out what triggers them to blow in a new study published in the journal Scientific Reports.

The Toba eruption was the largest volcanic eruption witnessed in history, which covered 2,800 cubic kilometers of the surrounding area in volcanic ash, causing enormous amounts of rain in Indonesia and India.

How exactly these huge amounts of magma are created (and why they erupt so violently) has been a cause of debate between scientists for a long time. It has been known that volcanoes erupt because of density and pressure, and generally it is a way that Earth can release excess heat and pressure. Still, the precise trigger has remained a mystery.

A group of researchers at Uppsala University and their international colleagues may have found some answers lying in millimeter-sized crystals called quartz crystals embedded in the volcanic ash and rock.

Quartz crystals grow in magma, and register chemical and thermodynamical changes before an eruption, which is similar to how tree rings record climate change, according to Dr David Budd, lead author of the study from the Department of Earth Sciences at Uppsala University.

"When the conditions in the magma change, the crystals respond and produce distinct growth zones that record these changes," he said in a statement. "The problem is that each 'tree ring'-analogue is only a few micrometers across, which is why they are extremely challenging to analyse in detail."

While studying the quartz from Toba, the researchers found that there was a difference in the composition and weight of the outer part of the crystals compared to the inside. Around the outside the crystals were heavier and contained a form of oxygen called 18O. On the inside, however, there was a lighter form called 16O.

According to the study authors, the ratio suggests that something in the magmatic system had changed drastically just before the big eruption. So what happened? The researchers think that when the magma melted, it took along with it a large volume of a nearby rock which contained the same ratio.

"This rock type also often contains a lot of water, which may be released into the magma, producing steam, and thereby an increased gas pressure inside the magma chamber," said Dr Frances Deegan, another author of the study. "This rapidly increased gas pressure and eventually allowed the magma to rupture the overlying crust, and send thousands of cubic kilometres of magma into the atmosphere."

HOW OFTEN DO SUPERVOLCANOES ERUPT?



THE NYIRAGONGO VOLCANO IN VIRUNGA NATIONAL PARK.


Luckily, supervolcanoes like these erupt very infrequently. Volcanic eruptions are measured by the Volcanic Explosivity Index (VEI,) with VEI 7 and VEI 8 eruptions being the most powerful.

Other than Toba, these are some of the most massive supervolcano eruptions in history:

• La Garita Caldera erupted approximately 27,800,000 years ago, and released 5,000 cubic kilometers of magma.
• Huckleberry Ridge in Yellowstone had a bulk ejection of 2,500 cubic kilometers about 2,100,000 years ago.
• Atana Ignimbrite in Chile erupted about 4,000,000 years ago, also ejecting 2,500 cubic kilometers.
• In 1815, the Tambora volcano on Sumbawa Island in Indonesia erupted in what is considered the largest ever eruption in recorded history. It was a VEI 7 on the VEI scale, but an estimated 100,000 people died from the effects, and it caused a global volcanic winter.

Although famous, eruptions such as Mount Vesuvius (Pompeii in 79 AD) and Mount St. Helens in 1980 were very small in comparison to these supervolcanic ones.

Researchers say that Toga's eruption in particular was so colossal it came close to wiping out humanity entirely. It's a matter of when, not if, supervolcanoes erupt again. Here's to hoping that we're better prepared when the next one happens!

Our Planet Doesn’t Just Support Life, It is Also Living Vessel

Mike White

TrendinTech
February 5, 2017

Although many people don’t realize, our planet doesn’t just support life; it too is alive. If you were to strip away all of the human-made structures, and even ourselves and other living creatures, you would still see waters flowing, volcanoes erupting, and trees blowing in the wind. Tectonic plates are thought to play a part in making the planet a livable place to live, and as far as we know, Earth is the only one in the solar system known to have them.

Beyond our solar system, astronomers have found various other planets – some of which may boast plate tectonics and could well be habitable. Even of these planets don’t hold tectonics that doesn’t mean to say there’s no geological activity going on there. Both the moon and Mars experience quakes, Jupiter’s moons have volcanoes and geysers, and evidence suggests that Mercury has a molten core (at least partly) and none of those have plate tectonics.

However, plate tectonics and geological activity aren’t the same. Ours is the only planet in the solar system that has a broken outer crust with plates that extend hundreds of kilometers beneath the surface. Where these plates shift against one another, they renew the surface, and at mid-ocean ridges, plates are pushed apart by rising magma forming a new crust. These are all essential processes that need to happen for the Earth continue as it is – without them, the planet would be as uninhabitable as Venus.

Plate tectonics also help to keep volcanoes active by ensuring the carbon cycle runs efficiently. A warmer climate will produce a lot of rain which ultimately aids in the extraction of carbon dioxide from the atmosphere. Then the gas is dissolved in raindrops and splashes on the rocks where chemical reactions take place that release carbon and other minerals from them. Eventually, the water will flow back to the ocean where carbonate rocks and organic objects like seashells will form. Where the carbonate settles on the bottom of the ocean, volcanoes are activated, and carbon is sprayed back into the atmosphere as carbon dioxide.

Fresh rocks are bought to the surface with thanks to plate tectonics, mountains are formed from plate tectonics, and diverse environments have been created because of plate tectonics. Brad Foley, a geophysicist at Penn State University, said, “Plate tectonics help keep volcanism active for a long time. If we didn’t have volcanism sending back carbon dioxide into the atmosphere, then the planet could get very cold. It would freeze over.” Plate tectonics are also helpful when it comes to removing elements from rock and carrying them to sea. Without plate tectonics we wouldn’t have such diverse environments either, so we have a lot to be thankful to them for.

Another thing that wouldn’t be without the help of plate tectonics is the hydrothermal vents that lie on the ocean floor. These vents are home to various marine life, and some experts have even predicted similar events could have given rise to the first instances of life on Earth. But, the real question lies in if plate tectonics are a requirement in order for life to start and survive. Lindy Elkins-Tanton is a planetary scientist at Arizona State University, and she says, “Plate tectonics is critical for the life we know and love as humans. But, it’s not necessarily required for life in a broader sense.” Just because Earth requires plate tectonics to maintain a regular carbon cycle, that doesn’t mean a different planet has the same requirement.

However, one thing that can be agreed upon is that plate tectonics could help coax life into existence but whether that’s necessary – who knows? Elkins-Tanton says, “We don’t understand enough about plate tectonics to understand whether it’s critical for habitability.” But, to try and prove this theory by looking at other planets outside our solar system is almost impossible. “We could barely detect it on our own planet, and we’re standing right on it”, says Elkins- Tanton. So, we may never really know if plate tectonics is needed, but for now, at least, we can still believe that Earth is the only planet truly alive.

These declassified maps show how the CIA saw the world at the height of theCold War

Christopher Woody

Business Insider

Feb 2, 2017

Perhaps more so than any other tool used by the clandestine services, an accurate map can mean the difference between success and failure, or life and death.

The CIA, renowned for its secrecy, has long kept its maps and cartographic methods under wraps.

But, in honor of the agency's Cartography Center's 75th anniversary, the CIA put a number of maps online, depicting how "the company" has viewed the world since its inception in the aftermath of World War II.


Suspected sites of missiles in Cuba, 1962CIA


President Franklin Roosevelt created the agency that would eventually become the CIA in the early 1940s. The map division produced a bevy of maps vital to strategic planning during the war, according to National Geographic.

The agency's mapmakers had a broad mission, asked to produce maps and data relevant to whatever national security issues the country may have encountered. In the process, "Geographers and cartographers amassed what would be the largest collection of maps in the world."

In a sign of how valuable maps were during the Cold War, the Soviet Union dedicated a great deal of resources and time to not only making exacting maps of foreign capitals and other cities, but also to make misleading maps of their own territory, meant to disrupt the movements of anyone who acquired those maps with nefarious intent.

In the early days, the CIA's maps were produced by hand, drawn in pen on translucent sheets that could be stacked, photographed, and printed. But the agency was one of the first to adopt digital technology.

"In 1966, a large working group, using a borrowed digitizer, compiled and digitized coastlines and international boundaries for the entire world—in a single weekend," the agency said in a release.

What maps got made varied with the geopolitical challenges of the moment, but as the maps below show, the quality never slacked.


CIA

CHINESE RAILROAD CONSTRUCTION IN THE MID-1950S.

CIA

OIL TRANSPORT AND REFINING FACILITIES IN THE MIDDLE EAST IN THE EARLY 1950S.


CIA

A MAP OF FRENCH AND VIET MINH AREAS OF OPERATIONS DURING THE 1950S.


CIA

INTERNATIONAL TRADE FLOWS IN THE 1950S.


CIA

SUSPECTED SITES OF MISSILES IN CUBA, 1962.


CIA

TRANSPORTATION ROUTES IN AND AROUND WEST AND EAST BERLIN IN THE 1960S.


CIA

THE CHINA-INDIA BORDER REGION IN 1963.


CIA

BANTUSTANS IN SOUTH AFRICA IN 1973.


CIA

ETHNIC GROUPS IN AFGHANISTAN IN 1979.


CIA

SOUTHERN LEBANON AND ENVIRONS IN 1977.


CIA

CENTRAL MOSCOW IN 1980.


CIA

POPULATION CHANGES DUE TO REFUGEE MOVEMENT ON THE AFGHANISTAN-PAKISTAN BORDER, 1982.


CIA

YUGOSLAVIA IN 1981.


CIA

VATICAN CITY, 1984.

Does an anomaly in the Earth’s magnetic field portend a coming pole reversal?

February 5, 2017
What’s north would become south

The Conversation

John Tarduno and Vincent Hare

The Earth is blanketed by a magnetic field. It’s what makes compasses point north, and protects our atmosphere from continual bombardment from space by charged particles such as protons. Without a magnetic field, our atmosphere would slowly be stripped away by harmful radiation, and life would almost certainly not exist as it does today.

You might imagine the magnetic field is a timeless, constant aspect of life on Earth, and to some extent you would be right. But Earth’s magnetic field actually does change. Every so often – on the order of several hundred thousand years or so – the magnetic field has flipped. North has pointed south, and vice versa. And when the field flips it also tends to become very weak.

On the left, the Earth’s magnetic field we’re used to. On the right, a model of what the magnetic field might be like during a reversal. NASA/Gary Glazmaier, CC BY

What currently has geophysicists like us abuzz is the realization that the strength of Earth’s magnetic field has been decreasing for the last 160 years at an alarming rate. This collapse is centered in a huge expanse of the Southern Hemisphere, extending from Zimbabwe to Chile, known as the South Atlantic Anomaly. The magnetic field strength is so weak there that it’s a hazard for satellites that orbit above the region – the field no longer protects them from radiation which interferes with satellite electronics.

And the field is continuing to grow weaker, potentially portending even more dramatic events, including a global reversal of the magnetic poles. Such a major change would affect our navigation systems, as well as the transmission of electricity. The spectacle of the northern lights might appear at different latitudes. And because more radiation would reach Earth’s surface under very low field strengths during a global reversal, it also might affect rates of cancer.

We still don’t fully understand what the extent of these effects would be, adding urgency to our investigation. We’re turning to some perhaps unexpected data sources, including 700-year-old African archaeological records, to puzzle it out.

Genesis of the geomagnetic field

Cutaway image of the Earth’s interior. Kelvinsong, CC BY-SA

Earth’s magnetic field is created by convecting iron in our planet’s liquid outer core. From the wealth of observatory and satellite data that document the magnetic field of recent times, we can model what the field would look like if we had a compass immediately above the Earth’s swirling liquid iron core.

These analyses reveal an astounding feature: There’s a patch of reversed polarity beneath southern Africa at the core-mantle boundary where the liquid iron outer core meets the slightly stiffer part of the Earth’s interior. In this area, the polarity of the field is opposite to the average global magnetic field. If we were able to use a compass deep under southern Africa, we would see that in this unusual patch north actually points south.

This patch is the main culprit creating the South Atlantic Anomaly. In numerical simulations, unusual patches similar to the one beneath southern Africa appear immediately prior to geomagnetic reversals.

The poles have reversed frequently over the history of the planet, but the last reversal is in the distant past, some 780,000 years ago. The rapid decay of the recent magnetic field, and its pattern of decay, naturally raises the question of what was happening prior to the last 160 years.
Archaeomagnetism takes us further back in time

In archaeomagnetic studies, geophysicists team with archaeologists to learn about the past magnetic field. For example, clay used to make pottery contains small amounts of magnetic minerals, such as magnetite. When the clay is heated to make a pot, its magnetic minerals lose any magnetism they may have held. Upon cooling, the magnetic minerals record the direction and intensity of the magnetic field at that time. If one can determine the age of the pot, or the archaeological site from which it came (using radiocarbon dating, for instance), then an archaeomagnetic history can be recovered.

Using this kind of data, we have a partial history of archaeomagnetism for the Northern Hemisphere. In contrast, the Southern Hemisphere archaeomagnetic record is scant. In particular, there have been virtually no data from southern Africa – and that’s the region, along with South America, that might provide the most insight into the history of the reversed core patch creating today’s South Atlantic Anomaly.

But the ancestors of today’s southern Africans, Bantu-speaking metallurgists and farmers who began to migrate into the region between 2,000 and 1,500 years ago, unintentionally left us some clues. These Iron Age people lived in huts built of clay, and stored their grain in hardened clay bins. As the first agriculturists of the Iron Age of southern Africa, they relied heavily on rainfall.

Grain bins of the style used centuries ago. John Tarduno, CC BY-ND

The communities often responded to times of drought with rituals of cleansing that involved burning mud granaries. This somewhat tragic series of events for these people was ultimately a boon many hundreds of years later for archaeomagnetism. Just as in the case of the firing and cooling of a pot, the clay in these structures recorded Earth’s magnetic field as they cooled. Because the floors of these ancient huts and grain bins can sometimes be found intact, we can sample them to obtain a record of both the direction and strength of their contemporary magnetic field. Each floor is a small magnetic observatory, with its compass frozen in time immediately after burning.

With our colleagues, we’ve focused our sampling on Iron Age village sites that dot the Limpopo River Valley, bordered today by Zimbabwe to the north, Botswana to the west and South Africa to the south.

What’s happening deep within the Earth, beneath the Limpopo River Valley? John Tarduno

Magnetic field in flux

Sampling at Limpopo River Valley locations has yielded the first archaeomagnetic history for southern Africa between A.D. 1000 and 1600. What we found reveals a period in the past, near A.D. 1300, when the field in that area was decreasing as rapidly as it is today. Then the intensity increased, albeit at a much slower rate.

The occurrence of two intervals of rapid field decay – one 700 years ago and one today – suggests a recurrent phenomenon. Could the reversed flux patch presently under South Africa have happened regularly, further back in time than our records have shown? If so, why would it occur again in this location?

Over the last decade, researchers have accumulated images from the analyses of earthquakes’ seismic waves. As seismic shear waves move through the Earth’s layers, the speed with which they travel is an indication of the density of the layer. Now we know that a large area of slow seismic shear waves characterizes the core mantle boundary beneath southern Africa.

Location of the South Atlantic Anomaly. Michael Osadicw/John Tarduno, CC BY-ND

This particular region underneath southern Africa has the somewhat wordy title of the African Large Low Shear Velocity Province. While many wince at the descriptive but jargon-rich name, it is a profound feature that must be tens of millions of years old. While thousands of kilometers across, its boundaries are sharp. Interestingly, the reversed core flux patch is nearly coincident with its eastern edge.

The fact that the present-day reversed core patch and the edge of the African Large Low Shear Velocity Province are physically so close got us thinking. We’ve come up with a model linking the two phenomena. We suggest that the unusual African mantle changes the flow of iron in the core underneath, which in turn changes the way the magnetic field behaves at the edge of the seismic province, and leads to the reversed flux patches.

We speculate that these reversed core patches grow rapidly and then wane more slowly. Occasionally one patch may grow large enough to dominate the magnetic field of the Southern Hemisphere – and the poles reverse.

The conventional idea of reversals is that they can start anywhere in the core. Our conceptual model suggests there may be special places at the core-mantle boundary that promote reversals. We do not yet know if the current field is going to reverse in the next few thousand years, or simply continue to weaken over the next couple of centuries.

But the clues provided by the ancestors of modern-day southern Africans will undoubtedly help us to further develop our proposed mechanism for reversals. If correct, pole reversals may be “Out of Africa.”

Well, This Might Be The Most Artistic Climate Change Ad You've Ever Seen

By Louise Jack
Feb 7, 2017

Charles Dance leads British stars of stage and screen in a poetic "Love Song" ode to Earth for climate charities.


Charles Dance


WHAT: "A Love Song", a poetic tribute to Earth from a group of U.K. charities and organizations committed to tackling climate change.


WHO: The Climate Coalition, Ridley Scott Associates

WHY WE CARE: When Charles Dance’s says, darkly, "I’ve heard talk of a quiet violence waiting at the water’s edge," one sits up and pays attention. But, although this film begins with loss and foreboding, it unfolds into a lyrical message of hope. Dance is joined by fellow actors Miranda Richardson, Jason Isaacs and David Gyasi. Each recites a section of a script written by British poet Anthony Anaxagorou after which the background soundtrack swells into a majestic choral version of Elbow’s Magnificent (She Says).


David Gyasi


The Climate Coalition is an alliance of more than 100 U.K. charities and other organizations, including WWF U.K., 350.org, Friends of the Earth, and Greenpeace U.K., all with an interest in combatting climate change. In a statement, the film’s director, Stuart Rideout, alludes to the current disturbing political attitudes to climate change, "We are entering difficult times in terms of how the world views and reacts to climate change. Engagement with the subject is more important now than ever, " he says. How right he is.