General Meteorology and Earth Science Thread

World's longest continental volcano chain in Australia: "Scientists have discovered the world's longest known chain of continental volcanoes, running 2,000 kilometers across Australia, from the Whitsundays in North Queensland to near Melbourne in central Victoria. The volcanic chain was created over the past 33 million years, as Australia moved northwards over a hotspot in Earth's mantle."

For those who wonder, the Andean volcanic belt is split in four sectors, each segment is not as long. Is it really longer than the Cordilleran belts and the Indonesian one, though?

edited 15th Sep '15 1:14:41 AM by SeptimusHeap

A new view of the content of Earth's core: "There is more oxygen in the core of Earth than originally thought. Geologists have discovered some new findings about Earth's core and mantle by considering their geophysical and geochemical signatures together."

Signs of ancient mega-tsunami could portend modern hazard: "Scientists working off west Africa in the Cape Verde Islands have found evidence that the sudden collapse of a volcano there tens of thousands of years ago generated an ocean tsunami that dwarfed anything ever seen by humans. The researchers say an 800-foot wave engulfed an island more than 30 miles away. The study could revive a simmering controversy over whether sudden giant collapses present a realistic hazard today around volcanic islands, or even along more distant continental coasts."

Technically, the controversy is more about whether such tsunamis can cross oceans rather than whether they exist, period.

NASA data suggests that Indonesia's forest fires could become the worst on record. Posting here due to the resulting haze.

Bumping, because today is the 30th anniversary of the Armero tragedy, the second-deadliest volcanic eruption of the 20th century. A moderately strong eruption of Colombia's Nevado del Ruiz volcano caused part of its icecap to melt, generating a mudflow that buried the town of Armero and a few other towns beneath, causing 25,000 victims despite there plenty of forewarning for both eruption and the mudflows. There was plenty of controversy about the Colombian's government handling of both the pre-disaster events and the disaster itself; the town has not been rebuilt.

<shudder> Lahars are scary. Not pyroclastic flow scary but definitely up there.

Actually I think footage of that particular event was used in my unit on volcanic hazards.

Earth not due for a geomagnetic flip in the near future, researchers show: "The intensity of Earth's geomagnetic field has been dropping for the past 200 years, at a rate that some scientists suspect may cause the field to bottom out in 2,000 years, temporarily leaving the planet unprotected against damaging charged particles from the sun. This drop in intensity is associated with periodic geomagnetic field reversals, in which the Earth's North and South magnetic poles flip polarity, and it could last for several thousand years before returning to a stable, shielding intensity.

With a weakened geomagnetic field, increased solar radiation might damage electronics—from individual pacemakers to entire power grids—and could induce genetic mutations. A reversal may also affect the navigation of animals that use Earth's magnetic field as an internal compass.

But according to a new MIT study in the Proceedings of the National Academy of Sciences, the geomagnetic field is not in danger of flipping anytime soon: The researchers calculated Earth's average, stable field intensity over the last 5 million years, and found that today's intensity is about twice that of the historical average.

This indicates that the current field intensity has a long way to fall before reaching an unstable level that would lead to a reversal."

Volcanic rocks hold clues to Earth's interior: "Earth's deep interior transport system explains volcanic island lava complexities, report scientists. Studies of rocks found on certain volcanic islands, known as ocean island basalts, have revealed that although these erupted rocks originate from Earth's interior, they are not the same chemically."

Study undercuts idea that 'Medieval Warm Period' was global: "A new study questions the popular notion that 10th-century Norse people were able to colonize Greenland because of a period of unusually warm weather. Researchers say the climate was already cold when the Norse arrived — and that climate thus probably played little role in their mysterious demise some 400 years later. On a larger scale, the study adds to building evidence that the so-called Medieval Warm Period, when Europe enjoyed clement weather, did not necessarily extend to other parts of the world."

Study finds 'frictional heat' as a new trigger for explosive volcanic eruptions: "Temperature may be more important than pressure in generating gas bubbles which trigger explosive volcanic eruptions, a new study into magma ascent has found. The study, which combined field observation, interpretation of monitored data and controlled laboratory experimentations, provides a strong argument for the integration of temperature as a key control in volcanic eruptions models."

Hurricane season this year started early: Hurricane Alex did form over the Bahamas islands in the first January week and developed into a Hurricane south of the Azores. It's now in the process of turning into an extratropical storm as it moved northward over the Azores islands.

January hurricanes are very uncommon in general. There was one 2005-2006 after the strong 2005 hurricane season. Alex is the first one to develop in January since 1938.

There has been a major earthquake and earthquake swarm in central Italy this night. 13 fatalities now, but they are probably going to rise.

And follow up 120 fatalities now.

Well, OK, multipost.

Massive 'lake' discovered under volcano could unlock why and how volcanoes erupt. Apparently Cerro Uturunku in South America volcano has such a large amount of water in its magma, that it is as much as a major lake like Lake Superior and the like.

A 7.4 Quake in Southern California? A Long Fault Could Make It Likelier. Discovered a while ago, two major fault zones in the "southland" - the Newport-Inglewood fault in LA and the Rose Canyon fault in San Diego - appear to be actually the same fault. And since one of the 4 parameters in maximum earthquake strength is the fault length, large earthquakes are thus more likely.

(Worth noting, although I don't remember the source offhand, that apparently the recent two centuries have been a seismic and climatic lull in California, with fewer extreme events happening than on average over a millennium or so)

Bumping this up from the depths, because Hawaii's Mauna Loa volcano has erupted at 11:30 PM HST on Sunday night. Summit region only so far.

First time an eruption's happened there since before I was born. Most of the activity's from Kilauea since it's closest to the hot spot. I'll be following this.

Looks like the eruption has moved out of the Mokuʻāweoweo caldera and onto the northeastern rift zone.

Here's a video of mountaineers being almost overtaken by a sudden eruption of Chile's Lascar volcano.

Going by SERNAGEOMIN's report it seems like the eruption commenced suddenly and without warning. Apparently the hikers escaped unharmed, though.

Someday I'll figure out the connection between unusual weather and waking up with a headache.

Lower air pressure? Storms and other heavy rain come from cells of lower air pressure arriving, which is also associated with older people feeling their arthritis acting up because their joints are more sensitive to those changes in air pressure.

I thought that was an old wives tale.

It's not. I broke the hell out of my ankle in 2005 and for the next two years my coworkers joked that they could tell when it was about to storm by watching me walk. It's still sensitive to pressure changes 17 years later.