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Deserts / Dry lands

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1 Teaching deserts

Atacama Desert. Desert adaptations. Desert landforms. Desert water table. Thermoregulation / Thermal comfort. Plant adaptations for deserts. Management of desertification. Snow in desert environments. Sahel desertification. *****Cities from scratch: watch new cities rise from the desert, jungle and sea. Massimo sur Twitter : "Kompsat-2 satellite captured this magnificent image over the sand seas of the Namib Desert in 2012. The blue and white area is the dry river bed of the Tsauchab. Black dots of vegetation are concentrated close to the river’s main ro. Looks like something straight out of the Dust Bowl. This was a dust storm (also called a haboob) today in Big Spring, TX! □ courtesy of Joe Scott. РоссиЯ □□ sur Twitter : "Wanna visit a region of geographical paradoxes? Go to #Russia'n #Siberia! In the Charskaya Valley the golden sands of the desert sit side by side with the wilderness of the taiga and the peaks of mountain ranges!

Stephen Lokier sur Twitter : "Aeolian sands from the Rub al Khali (Empty Quarter) of the UAE. Well-sorted, well-rounded quartz grains with a hematite coating (texturally and mineralogically mature. Frosted surfaces, typical of aeolian sands, records abras. This timelapse of Namib desert sand dunes travelling hundreds of meters in 30yrs is somewhat mesmerizing… Theconversation. At this time of year in Europe, you may have noticed something in the air.

theconversation

Dust-laden winds blowing from the Sahara desert cause “seasonal haze episodes” that can even result in mud or “blood” rain. In West Africa, which experiences haze episodes between November and March, the dust-laden trade wind is called the Harmattan and has important implications, not only for soil fertility but also radio communication, visibility at airports and in shipping lanes, and also on livelihoods – and health. Dry skin and cracked lips are regular symptoms of exposure to the haze. But it presents more serious problems for asthmatics – and can lead to silicosis, a lung disease caused due to a high content of quartz in the dust.

Arid. Chile's Atacama desert: World's driest place in bloom after surprise rain - BBC News. Image copyright EPA.

Chile's Atacama desert: World's driest place in bloom after surprise rain - BBC News

*****By Using High-resolution Satellite Imagery to Survey Drylands, Researchers Boosted Estimates of Global Forest Cover by 9% - Geolounge. Two-fifths of the Earth’s surface is covered by drylands but the extent of forests in this biome was poorly understood until a group a researchers used high-resolution satellite imagery to remotely sense forest cover.

*****By Using High-resolution Satellite Imagery to Survey Drylands, Researchers Boosted Estimates of Global Forest Cover by 9% - Geolounge

What are Drylands? Drylands are areas defined by a scarcity of water. Precipitation in these areas is offset by evaporation and evapotranspiration by plants. Drylands are areas where the average annual rainfall is less than water loss through evaporation and transpiration. *****Fennec foxes’ remarkable ears help keep them cool in the desert and pick up the sounds of prey underground (Image: Anass Errihani) Desertification vulnerability #Environment #World. Great Green Wall Sahel-Sahara project aims to combat land degradation #agroforestry A Wall Worth Building. China's 'Great Green Wall' Fights Expanding Desert. Would You Stay if Your Homeland Became a Desert?

China's 'Great Green Wall' Fights Expanding Desert

In April in the Gobi Desert, herders like Buyintegedele plant corn that they’ll harvest in October—if it survives. April is also high season for sandstorms, a result of desertification—the transformation of arable, hospitable land into desert. These fierce storms can occur three to 10 times per month, destroying crops and damaging infrastructure. The Song of the Dunes. My decades-long fascination with the East Mojave Desert truly began while doing field research for my masters’ degree in environmental studies.

The Song of the Dunes

My thesis topic was studying the impacts on desert vegetation from human intrusion in the form of linear corridors (such as roadways, pipelines, and electric transmission lines). Unfortunately, graduating on time required that my field work be done mostly in the summer. California’s superbloom from space. See more Images of Change. The desert's 'skin': What it is, and why we need to look after it #environment. Physics of booming and burping sand dunes revealed. Avalanching sand from dune faces in Death Valley National Park and the Mojave Desert can trigger loud, rumbling “booming” or short bursts of “burping” sounds — behaving as a perfectly tuned musical instrument.

Physics of booming and burping sand dunes revealed

This sound is persistent and the dunes “sing” in frequencies ranging from 70 to 105 Hertz, with higher harmonics. How human error could have created the Sahara desert. Once upon a time, the Sahara was green.

How human error could have created the Sahara desert

There were vast lakes. Hippos and giraffe lived there, and large human populations of fishers foraged for food alongside the lakeshores. The “African Humid Period” or “Green Sahara” was a time between 11,000 and 4,000 years ago when significantly more rain fell across the northern two-thirds of Africa than it does today. *****Superbloom at Carrizo Plain National Monument in CA (Robyn Beck/AFP) (rapid reproduction cycles) How Australia's climate compares to the rest of the world. Dust devils and dunes. THE Salar de Gorbea, at the southern end of the Atacama desert, in Chile, is one of the most hostile places on Earth.

Dust devils and dunes

It receives virtually no rainfall and the little water it does host is contained in ponds both acidic and salty. It therefore has no vegetation. It is, though, the site of some of the most extraordinary dunes on Earth. Most dunes are made of sand: grains of silica that are 2mm across, or less. There are exceptions. Thunk: Flood Death Valley? Since Death Valley is below sea level could we dig a hole to the ocean and fill it up with water?

Thunk: Flood Death Valley?

—Nick Traeden Yes! We can do anything we want. We shouldn't do this, though, because it would be gross. Death Valley is an endorheic basin[1]"Big hole" in California. Now, if you're the sort of person who's into world records, you might have heard that the hottest place on Earth was Al Azizia, Libya. It turns out Al Azizia has recently been stripped of its record. Except it's not quite settled. These records were recorded with modern instruments and are considered reliable. Now, back to Nick's question.[5]This is nowhere NEAR the record for "most boring digression into world record trivia. " What is the largest desert on earth? It’s covered by a permanent ice sheet that contains 90% of the Earth’s fresh water.

What is the largest desert on earth?

Only 2% of the continent isn’t covered by ice, and this land is strictly along the coasts, where all the life that is associated with the land mass (i.e. penguins, seals and various species of birds) reside. The other 98% of Antarctica is covered by ice which averages 1.6 km in thickness. There are no permanent human residents, but anywhere from 1,000 to 5,000 researchers inhabit the research stations scattered across the continent – the largest being McMurdo Station, located on the tip of Ross Island. Beyond a limited range of mammals, only certain cold-adapted species of mites, algaes, and tundra vegetation can survive there. Despite having very little precipitation, Antarctica still experiences massive windstorms.