Indonesia warns of further eruptions after volcano spews ash
Indonesia warns of further eruptions after volcano spews ash
KARO, Indonesia (Reuters) – Indonesian officials warned on Monday against the prospect of further eruptions from an active volcano on the island of Sumatra after it emitted a huge column of ash, causing panic among residents.
Mount Sinabung, which has seen a spike in activity since 2010, erupted for around nine minutes on Sunday, sending clouds of volcanic ash 7 km (4.4 miles) into the sky.
Although no casualties were reported, officials monitoring the volcano warned of possible fresh eruptions.
„After the eruption, from midnight until 6 a.m., there were a few aftershocks,” said Willy, a scientist at a Sinabung observatory post, who uses one name, like many Indonesians.
Authorities left unchanged the alert level for Sinabung, but urged residents to use face masks and keep indoors to guard against volcanic ashfall.
Mount Sinabung, which is 2,460 m (8,071 ft) high, is among Indonesia’s most active volcanoes, but had been inactive for four centuries before its 2010 eruption. Indonesia has nearly 130 active volcanoes, more than any other country.
(Reporting by Yudhistira; Writing by Kanupriya Kapoor; Editing by Clarence Fernandez)
The ocean is a big bathtub full of 326 million cubic miles (1.3 billion cubic kilometers) of water, and somebody has unplugged the drain.
Every day, hundreds of millions of gallons of water stream from the bottom of the ocean into Earth’s mantle as part of a very wet recycling program that scientists call the deep water cycle. It works like this: First, water soaked up in the crust and minerals at the bottom of the sea both get shoved into Earth’s interior at the undersea boundaries where tectonic plates collide. Some of that water stays trapped (some studies estimate that two to four oceans’ worth of water are sloshing through the mantle), but large amounts of that water get spewed back to the surface via underwater volcanoes and hydrothermal vents. [50 Interesting Facts About Planet Earth]
It’s not a perfect system; scientists think there’s currently a lot more water plunging into the mantle than spewing out of it — but that’s OK. Overall, this cycle is just one cog in the machine that determines whether the world’s oceans rise or fall.
Now, in a study published May 17 in the journal Geochemistry, Geophysics and Geosystems, researchers report that this cog may be more improtant than previously thought. By modeling the fluxes in the deep water cycle over the last 230 million years, the study authors found that there were times in Earth’s history when the gargantuan amount of water sinking into the mantle played an outsize role in sea level; during those times, the deep water cycle alone may have contributed to 430 feet (130 meters) of sea-level loss, thanks to one world-changing event: the breakup of the supercontinent Pangaea.
„The breakup of Pangaea was associated with a time of very rapid tectonic plate subduction,” lead study author Krister Karlsen, a researcher at the Centre for Earth Evolution and Dynamics at the University of Oslo, told Live Science. „This led to a period of large water transport into the Earth, causing associated sea-level drop.”
Death of a supercontinent
About 200 million years ago, the supercontinent Pangaea (a landmass consisting of all seven continents we know today) started to split, sending massive slabs of land careening in all directions.
As these continental plates spread apart, new oceans appeared (beginning with the Atlantic, roughly 175 million years ago), huge rifts in the seabed cracked open and ancient slabs of underwater crust plunged into the fresh voids. Gargantuan amounts of water that were trapped inside those sinking chunks of crust moved from the planet’s surface into its deep interior.
Building on previous studies of Earth’s tectonic plates over the last 230 million years, the researchers modeled the approximate rates that water entered — and left — Earth’s mantle. The faster a water-rich plate fell into Earth, the farther it could subduct before its water content was evaporated by the high heat of the mantle. According to the team’s calculations, this imbalanced the deep water cycle enough to result in millions of years of extreme water loss.
Of course, there is more to sea level than just the movement of very deep water, Karlsen said, and this study doesn’t account for other sea level changing processes like climate change or ice sheet coverage. Even as massive amounts of water sink into the mantle, actual sea levels can spike and plummet by hundreds of feet on much shorter timescales.
Right now, the ocean is in the midst of another sea level spike, thanks largely to manmade climate change (estimates vary, but sea levels will probably rise anywhere from 6 to 16 feet over the next century). Sadly, all those billions of gallons of sea water pouring into the mantle right now can’t save us from this dangerous trend.
„While the deep water cycle can effectively change sea level over hundreds of millions to billions of years, climate change can change the sea level in zero to 100 years,” Karlsen said. „For comparison, the present-day sea level rise associated with climate change is about 0.1 inches (3.2 millimeters) a year. The sea level drop associated with the deep water cycle is about 1/10,000 of that.”
2019 Planet Earth
Highs: Mount Everest, Hawaii, the Great Barrier Reef, the Amazon River.
Lows: Disease, competition for resources, Justin Bieber, wars, Ohio.
On a universal scale, Earth is a speck, a smallish orb in the ever-expanding cosmos finished in azure blue with white-wisp landau-style accents. But an innocuous appearance belies its spectacular performance numbers. It’s the fastest vehicle we’ve ever tested, and the heaviest. It’s the only one big enough to cast a shadow across the entire surface of the moon. It doesn’t defy physics but is, in fact, the only known spot where sentient beings recognize that physics is a thing. It’s groovy without being retro. It’s Earth, and it’s home.
It’s also expensive. In 2009, Greg Laughlin, now a professor of astronomy and astrophysics at Yale, estimated the total value of Earth, its resources, and all the things that make it such a nice place to live at $5 quadrillion-dwarfing the combined valuation of the other planets with which it shares a solar system. Account for inflation, add in humanity’s accumulated wealth, and tack on $300 for Apple CarPlay, and you’re at a total estimated as-tested price of $6,208,198,254,850,300. No one owns Earth, but 7.7 billion humans are supposed to do regular maintenance.
„Earth’s spin is something that we think was set by a collision with a large planet that created the moon,” explains Lars Bildsten, the director of the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara. And the moon’s gravitational pull causes tidal friction that slows down Earth’s rotation ever so slightly. So, in effect, the moon acts as a brake on Earth’s 1037-mph equatorial spin-with the 13,169,533,690,000,000,000,000,000-pound (estimated) planet’s days getting about 1.8 milliseconds longer ever’y century. But don’t sweat the braking distance. It will still be spinning when, in about 5 billion years, the sun becomes a red giant star that consumes the inner planets and maybe Earth, too. That will suck.
Earth laps the sun at an average speed of 66,627 mph. That means it could cover the Nürburgring Nordschleife’s 12.9 miles in just 0.697 second, obliterating the Porsche 919 Hybrid Evo’s lap record by 5 minutes 18.85 seconds. Plus, it has been operating with Level 4 automation for more than 4.5 billion years and rides in such comfort that we all sleep on it. Handling is communicative but upset by the occasional tremor, tectonic shift, or volcanic eruption.
Earth’s not-so-secret weapon is the sun, an external-combustion powerhouse. Knocking out 384.6 yottawatts, the sun’s ongoing nuclear fusion reaction is the ultimate source of Earth’s energy. In carspeak, that’s 515,570,095,700,000,000,000,000 horsepower-about as much as 719, 065,684,000,000,000,000 Dodge Challenger Hellcats.
Earth uses that solar energy well thanks to an atmoshere that blocks much of the nasty ultraviolet rays and keeps things temperate, growing, and lushly endowed with tasty oxygen. It’s an automatic climate-control system that’s worked to humanity’s advantage since the last ice age ended 11,700 years ago. Lately, there have been some concerns about the system’s continued reliability. And due to the monumental development cost, no follow-up model is planned.