Rapid Earth Changes in Historic Times

first_imgWhat happened to the Sahara desert? What’s going on in Java, man? Geologists are surprised sometimes by recent major changes.Sahara Grassland?Science Daily asks an intriguing question about something most people probably don’t know: “6,000 years ago the Sahara Desert was tropical, so what happened?”As little as 6,000 years ago, the vast Sahara Desert was covered in grassland that received plenty of rainfall, but shifts in the world’s weather patterns abruptly transformed the vegetated region into some of the driest land on Earth.For scientists trained to think in millions of years, that’s a huge change in the ‘geological blink of an eye,’ as they are wont to say. Scientists from Yale and from Texas A&M think it’s due to changes in prevailing winds that affected rainfall, but why so permanent? This is climate change you can’t blame on fossil fuels. “We know that 6,000 years ago, what is now the Sahara Desert was a rainy place,” says Robert Korty from Texas A&M.Java CrystalsScience Magazine discusses one Fidel Costa—not Castro—who reads crystals. He is studying a volcanic eruption that occurred 4,000 years ago in Indonesia. Costa tries to read clues from crystals as small as lentils about why the Gede volcano erupted so quickly, to figure out when it might erupt again.Already, the few researchers adept at using the technique have found that magma can tear through the crust at searing velocities, and that volcanoes can gurgle to life in a geologic instant. Instead of taking centuries or millennia, these processes can unfold in a matter of decades or years, sometimes even months, says Kari Cooper, a volcano geochemist at the University of California, Davis.How quickly can things change underground to affect the surface? In just months or days, magma lurking in chambers can “mobilize rapidly,” the teams reported in the article say. Just because scientists can’t detect magma chambers easily doesn’t mean volcanoes like Mt. Hood don’t endanger nearby population centers. Within a century or less, magma from long-dormant volcanoes can start moving. In fact, “vats of liquid magma may only exist immediately prior to an eruption.”They have found that slugs of magma can rise 10 kilometers in roughly 10 minutes. “It’s like a freight train,” she says.The new “mush model” represents a change in thinking less than a decade old. It “suggests that magma may liquefy and erupt even more quickly than many researchers thought.” Reporter Julia Rosen quotes scientists calling the new model a “game changer” and a “surprise” that indicates to laypeople that even the experts can undergo rapid changes in thinking.See also Calvin Miller’s paper in PNAS, “Eruptible Magma,” about geophysicists’ frustration trying to locate magma chambers under volcanoes. There are “Key questions to be addressed if we are to understand magma systems and the eruptions that they produce,” he says. Some geologists are suspecting that “durations within the eruptibility window are interpreted to be short to extremely short” on the range of one to 10,000 years.Madagascar TestSo when volcanologists find anomalies, we begin to understand that maybe there’s a lot they don’t understand. For instance, a press release from Washington University in St. Louis wonders “What’s up with Madagascar?” Specifically, “Why are there volcanoes on an island that isn’t near any tectonic boundaries?” That’s a clue of an impending eruption in a dormant paradigm. The article speaks of millions of years, but how certain can anyone be with this kind of talk?Madagascar, the big island off the east coast of Africa with the lemurs and baobabs, is thought to be sitting in the middle of an old tectonic plate, and so, by the rules of plate tectonics, should be tectonically quiet: few earthquakes and no volcanoes.But it’s not. The island has been away from tectonic action for the past 80 million years, said Martin Pratt, research scientist in earth and planetary sciences at Washington University in St. Louis, yet it experiences about 500 earthquakes per year.The island also has volcanoes that have been active within the recent geologic past. “Having active volcanoes in Madagascar is like having erupting volcanoes in St. Louis,” said Michael Wysession, professor of earth and planetary sciences. “You have to ask yourself, ‘What are they doing there?’”The hero of the story is quick on his storytelling: “150 million years ago,” blah blah blah, then “90 million years ago,” stuff happened. An invisible slab fell off the mantle. He’s got it all figured out – till the next paradigm shift.Update 12/07/16: Greenland lost up to 90% of its vast ice fields several times for extended periods, according to an article on Live Science. Although the article mentions millions of years, it also speaks of “massive and rapid ice loss.” Once again, this kind of change was unexpected; “its surface ice was more variable than once thought.” The article does not mention warm periods from history in the time of the Vikings, who lived and farmed along Greenland’s coast. Long before the Industrial Revolution, these times of “green land” could not have been due to anthropogenic global warming.For more on Greenland’s ice sheet dynamics, see Phys.org, Science Daily, and another Science Daily piece. Two papers in Nature go into detail: #1 about extended ice-free periods in the Pleistocene, and #2 about “rapid and global changes” in the Greenland ice sheet.And Greenland is not alone. Another research summary in Nature says “As Earth emerged from the last ice age more than 10,000 years ago, West Antarctica … warmed two to three times faster than the rest of the planet.” See also Science Daily‘s report, “Information theory offers new way to read ice cores.” Readers may not be aware that ice core data is “packed with noise and error, making the climate story hard to read.”Update 12/16/16: The BBC News makes an astonishing claim about one of the driest places on earth: Chile’s Atacama Desert. It once had lakes and wetlands. Was that millions of years ago? No; just thousands. In fact, “the region may have been habitable for early settlers.”  Live Science says there is new archaeological evidence for settlements there that no one had bothered to look for before. There are also fossils of marine life deep in the sediments. See photos on Phys.org of how the desert looks today. It gets 15mm of precipitation per year now; some parts get none.You can measure crystals in the lab today, and hike around Madagascar in the present. That doesn’t give you a crystal ball into mythical worlds in deep time. There’s something really significant about that phrase, “than many researchers previously thought.” Remember, what they previously thought was gospel truth, taught in the textbooks. So when is the next “whoops” moment? (Visited 81 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

New year, new schools for Gauteng

first_img13 January 2010 One-and-a-half hours – that’s how long it would have taken learners from Lawley to get to school were it not for Deputy President Kgalema Motlanthe’s drive to get a new school up and running in the suburb in the south of Johannesburg. Lawley Secondary School in Lawley opened on the first day of the 2011 school calendar, 12 January, with 200-plus learners from the local community. It is the first secondary school in the suburb and one of seven new schools opened across the province. “This school is a demonstration of government working together,” said Gauteng Premier Nomvula Mokonyane, who attended the opening along with Motlanthe, Johannesburg Executive Mayor Amos Masondo, and Gauteng Education MEC Barbara Creecy. After residents pointed out the need for a secondary school in the area, Motlanthe committed himself to ensuring that the need was met. It took only eight weeks to set up the school, which is made up of prefabricated buildings. Creecy spoke of the “Motlanthe magic” regarding Soshanguve Technical Secondary School, which improved its results by 50% after Motlanthe intervened. She hoped this same magic would stay with Lawley Secondary to ensure it produced 100% pass rates in the future. “This community has an excellent opportunity to set the standard for the school. You have a blank sheet, no baggage, so you can move straight to becoming a school of excellence. Those who will join the school in the future will measure themselves against the standard set by the learners in this court,” said Motlanthe. He appealed to teachers, students and parents to perform their roles to the best of their ability. “The future of the school depends on what both students and teachers put in.” Skumbuzo Sibanda, a maths and social science teacher, said there was a desperate need for a secondary school in Lawley. “It is the first non-school fee paying secondary school in the area and it cuts down on the great distances that the children had to travel to school every day. We are ready and willing to take the school to new heights.” In his vote of thanks, Masondo urged educators to arrive on time, not neglect their duties and refrain from abusing their learners. As to the learners, Masondo reminded them of their responsibilities to arrive at school on time, do their school work and respect their educators. Grade Eight pupil Mojalefe Masa said: “I’m happy to start my first day of high school at a new school. If the school wasn’t here I would have to go to Ennerdale and it would take me one hour 30 minutes every day.”Pupil numbers While there are only 200 children and 11 teachers at present, the school is able to accommodate many more. Creecy credits this to the fact that many parents had already enrolled their children at schools in neighbouring Lenasia and Ennerdale. “Now that the school is up and running we can say to the community, ‘Look it’s here,’ and start transferring those learners who are in Lenasia and Ennerdale to Lawley Secondary,” she added. She explained that while the government was unable to commit to a brick and mortar structure replacing the prefabs any time soon, residents must note that “the structures are insulated, they are SABS approved and have a 20-year life span … There are windows, doors and black boards. The structures serve the purposes for which they are meant.” Gauteng has a shortage of 212 schools, which Creecy accredits to the large number of people who migrate to the province. There were 13 other schools at different levels of completion that were to be opened this year, she said. While some were permanent structures, others, like Lawley, were temporary prefabricated structures. Both Creecy and Mokonyane stressed the importance of these prefab schools, which can be set up quickly and accommodate the thousands of learners needing a place to study. “We need to look at the use of alternative structures in the future … It is a myth that permanent structures must be brick and mortar. There are other schools here in Gauteng that have prefabricated classrooms as a means of additional classroom space,” Mokonyane pointed out. Creecy confirmed that there were 2 000 mobile classrooms on order to be delivered over the next few months, which would satisfy the high need for supplementary classroom space at existing schools and make up many of the new schools to be opened this year. Source: City of Johannesburglast_img read more

Strange ’80s Synth Music for Horror and Fantasy Films

first_imgGo upside down with these killer royalty free, retro-style synth tracks.Image via Shutterstock.When it comes to the finest royalty free synthesizer tracks, we’ve got what you need. From our previous retro-creepy Chilling ’80s Synth Mixtape and the recently popular Futuristic Sci-Fi Synth for noir dramas, our composers continue to produce stellar royalty free tracks for your projects.Image via Shutterstock.Whether you’re working in urban horror, retro fantasy, or even futuristic noir, these tracks will evoke a dark and otherworldly setting. Filmmakers and videographers often say that sound is everything, and in this genre, that’s absolutely true. Give your project the soundtrack it deserves with this ready-to-use playlist.Image via Shutterstock.If you like these tracks, be sure to check out these other curated synthesizer playlists.Chilling ’80s Synth MixtapeFuturistic Sci-Fi Synthlast_img read more

Finance Minister Arun Jaitley Leader of Rajya Sabha, Azad Leader of Opposition

first_imgArun Jaitley was named as the Leader of the House in Rajya Sabha on Monday, while Congress veteran Ghulam Nabi Azad was declared the Leader of the Opposition.Rajya Sabha Chairman Hamid Ansari made the announcement.Ansari said Parliamentary Affairs Minister M Venkaiah Naidu had written to him on June 2 informing that Jaitley will the Leader of the House in Rajya Sabha.He said the letter regarding Azad being made the Leader of Congress came to him on Sunday.Jaitley (61), a senior BJP member was earlier Leader of Opposition in the Rajya Sabha during UPA government, while Azad (65) was Union Health Minister.Both Jaitley and Azad lost elections from Amritsar in Punjab and Udhampur in Jammu and Kashmir respectively in this Lok Sabha polls but the tenure of their Rajya Sabha membership still remains.Jaitley had lost to Amarinder Singh of Congress while Azad lost the Lok Sabha polls to BJP’s Jitendra Singh, who is now Minister of State in PMO.While Jaitley is a member of Rajya Sabha from Gujarat, Congress leader Azad is a member from Jammu and Kashmir.-With inputs from PTIlast_img read more