My Science School

The Kalahari Desert is not really a desert, but rather a large arid to semi-arid sandy area in southern Africa, covering much of Botswana and parts of Namibia and South Africa. Though it is semi-desert, it has huge tracts of excellent grazing after good rains and is rich in wildlife.

The Kalahari has existed as an inland desert since the Cretaceous period (65-135 million years ago). It has experienced both periods of greater humidity and more aridity, documented in fossil dune fields. It was during a period of greater rainfall that the Makgadikgadi Depression in northern Botswana was formed. The former lake at one point covered 23,000 square miles (60,000 square kilometers), about the same size as Lake Victoria today. The dry riverbeds that now only hold water when it rains are also from such periods.

Credit: New World Encyclopedia

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The Gobi Desert straddles Mongolia’s southern border with China’s autonomous region of Inner Mongolia. It is a cold desert formed in the rain shadow of the Himalayas. The world’s highest mountain chain blocks clouds from the Indian Ocean from making it over the Tibetan Plateau and into the Gobi area.

During the late Cretaceous, some 70-80 million years ago, the Gobi region was a lot different. Parts of it were covered by dense conifer forests, criss-crossed by streams and dotted with lakes. Today, though, thanks to the desert’s barren, rock-strewn landscapes, paleontologists have found so many incredible fossils. The rocks from the lush dinosaur age are already exposed at the surface and ready to be explored.

The first-ever positively identified dinosaur eggs became one of the first sensational finds from a rocky outcrop called the Flaming Cliffs. Andrews thought the eggs belonged to a dinosaur called Protoceratops, a small hornless relative of Triceratops. Intriguingly, in other finds, a feathered carnivorous dinosaur called Oviraptor had also been found fossilized on top of Protoceratops eggs. In the 1990s scientists discovered that the eggs actually belonged to Oviraptor and these fossils were the first known evidence of dinosaur brooding behavior, a further evolutionary link with birds. Sadly, because of scientific naming rules, Oviraptor will always bear the Latin name “egg plunderer”.

Credit: EARTH ARCHIVES

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A rock that is shaped like a mushroom! What’s interesting is how the rock gets that shape. The strong winds blowing across desert landscapes erode the base of massive boulders more than the top. Over many years, this results in a thin stem supporting a broad cap - a mushroom rock.

Mushroom rock is a naturally occurring rock with the shape of a mushroom. The rocks are deformed in a variety of ways due erosion and weathering, glacial action, and sudden disturbances. Mushroom rocks are generally formed due to such deformations. We will learn about mushroom rocks associated with wind Erosional Landforms/ Aeolian Landforms.

• Mushroom Rock, also known as a perched rock or pedestal rock, is a boulder balanced on a pinnacle rock or over another boulder or in some other position.
• Rainwash generally removes the fine debris from around the boulder, causing some elevated rocks to develop.
• Mushroom rocks are usually found with a strong capping and crumbling or exudation along their edges.
• these types of rocks are generally found in deserts.

Formation of Mushroom Rocks

• In mushroom rocks, the wind-carried sand rarely rises more than three or four feet above the ground, although the concentration of the sand is highest at eighteen inches closest to the ground.
• As a result, the sandblast or abrasion effect will be greatest at or near the ground level.
• The upstanding rocks at their bottoms are undercut by continued abrasive action, resulting in Rock pedestal or Mushroom rocks.

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The warming climate is having an impact on Antarctica and its large penguin population. Here's a firsthand account of a trip through the frozen continent by an agriculture and environment scientist

No one owns Antarctica, but the penguins call it home. A frozen landmass that is over four times bigger than India, it has become a bellwether of the climate crisis.

Last year, a large chunk of ice-1.270 sq. km wide-split from the continental shelf causing concern among scientists. Was it due to climate change? Scientists are not sure. But what they know is that the rate of ice loss in Antarctica has tripled since 2012 compared to two decades earlier. Large chunks are splitting regularly from ice shelves, often requiring maps to be redrawn. The warming climate is having an impact on the 6-km-deep ice sheets and the resident penguin population.

Home of penguins

An estimated 12 million penguins live in Antarctica, though it is not their only habitat. Of the 18 species, only five live in Antarctica, including the renowned emperor penguins who march across the frozen tundra in a mating ritual that was featured in the documentary. "March of the Penguins" (Unfortunately, a new report forecasts that the entire population of emperor penguins may disappear by the year 21001)

Inspired in part by the movie and a desire to see the impact of climate change, I flew with two friends to Antarctica a few years ago. It was quite an adventure.

A plane took us from Punta Arenas, Chile, to the Chilean air base on King George Island. As it landed, a group of curious gentoo penguins came out to greet us. They were probably wondering who we were and why we were invading their space! We saw more of their cousins and their colonies as well as elephant seals and leopard seals when we explored the land and the sea over the next few days.

Cause for concern

About 90 per cent of the world's ice and 70 per cent of fresh water is in Antarctica. Some have calculated that if all of Antarctica's ice melted, sea levels would rise 60 to 70 m. drowning all coastal cities. Should we be concerned? Most certainly, as we would want to bequeath a better planet to future generations.

Antarctica is regarded by scientists as the perfect place to do research on flora and fauna, climate and a variety of issues-so there are 70 research stations involving 29 countries. Though there is no native human population, visiting researchers hope to find new organisms or data that could reveal the Earth's climate history and signs of a changing environment.

 

Living and doing research in a place, where temperatures can dip to minus 90 degrees Celsius and dark winters last six months, can be a challenge in the best of times. But it became a bigger challenge during the pandemic. In December 2020, the Chilean research station reported 36 COVID cases and the affected persons had to be evacuated to their home country.

New research

In 1985, British scientists discovered a hole in the ozone layer above Antarctica, which revealed the damage done to the Earth's atmosphere by manmade chemicals. In 2012, U.S. researchers discovered that Antarctica was melting twice as fast as previously thought. They also found that a warming ocean west of Antarctica would enable the king crab to move from the deep sea to shallower waters, making it a big predator and disrupting the ecosystem.

In 2017, India's polar biologists stumbled upon a species of moss they named Bryumbharatiensis. How had moss survived in this barren landscape? Dr Felix Bast, a member of the Indian research team, observed that the moss is nourished by penguin poop, which contains nitrogen and does not decompose in a frigid climate.

Impact of climate change

Sadly, Antarctica will not remain a winter wonderland for long on account of climate change. A group of scientists led by Stephen Rintoul have presented two stark images of Antarctica by 2070. In Vision 1, assuming global air temperatures rise 2.9 degrees Celsius, they predict sea levels will rise 27 cm, ice sheets will be reduced by 23 per cent and damage to the ecosystem will be most severe. In Vision 2, assuming a 0.9 degrees Celsius temperature rise, sea levels will rise only 6 cm, ice shelf loss will be 8 per cent, and damage to the ecosystem will be less severe. The outcomes will be determined by the climate actions we take in this decade. If global warming remains unchecked, it is quite possible that Antarctica will "be the world's only habitable continent by the end of this century," warns Sir David King, former Chief Scientist to the British government. Will humanity rise to the climate challenge?

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The Alps glaciers in Switzerland are on track for their highest mass losses in at least 60 years of record keeping, data shared exclusively with Reuters shows. By looking at the difference in how much snow fell in winter, and how much ice melts in the summer, scientists can measure how much a glacier has shrunk in any given year. Since last winter, which brought relatively little snowfall, the Alps have sweltered through two big early summer heatwaves.

During this heatwave, the elevation at which water froze was measured at a record high of 17,000 feet - at an altitude higher than Mont Blanc's compared with the normal summer level of between 9,800-11,500 feet.

"It's really obvious that this is an extreme season," Swiss glaciologist Andreas Linsbauer said, shouting over the roar of rushing meltwater as he checked the height of a measuring pole jutting out of the ice on the massive Morteratsch Glacier in Switzerland. The measuring poles he uses to track changes in the depth of the pack are at risk of dislodging entirely as the ice melts away and he needs to drill new holes.

Vanishing glaciers are already endangering lives and livelihoods. Further, Swiss residents worry that the glacier losses will hurt their economy. Some area ski resorts of the Alps, which rely on these glaciers, now cover them with white sheets to reflect sunlight and reduce melting.

Mountain meltdown

Most of the world's mountain glaciers-remnants of the last ice age-are retreating due to climate change. But those in the European Alps are especially vulnerable because they are smaller with relatively little ice cover. Meanwhile, temperatures in the Alps are warming at around 0.3C per decade-around twice as fast as the global average

If greenhouse gas emissions continue to rise, the Alps glaciers are expected to lose more than 80% of their current mass by 2100. Many will disappear regardless of whatever emissions action is taken now, thanks to global warming baked in by past emissions, according to a 2019 report by the UN Intergovemmental Panel on Climate Change

The dire situation this year raises concern that the Alps glaciers might vanish sooner than expected. With more years like 2022, that could happen, said Matthias Huss who leads Glacier Monitoring Switzerland (GLAMOS). "We are seeing model results expected a few decades in the future are happening now." Huss said. "I not expect to see such an extreme year so early in the century."

ALPS FACTS

• Located within the continent of Europe, the Alps mountain range is more than 1,000 km long.

• Though it spans several countries from France to Albania, it is Switzerland and Austria that are considered to be the Alpine heartland.

• The Alps is crucial for the livelihood of Europe as it provides water for drinking, irrigation, and hydroelectric power.

• Given its vastness and varied mountain elevation, the Alps has a huge impact on the weather patterns and the natural environment of the continent. In short, when the Alps is affected, it will have a bearing on several parts of the continent.

Himalayan thaw

Himalayan glaciers are also on track for a record ice loss year. When the summer monsoon season arrived in the Kashmir region, for example, many glaciers had already shrunk drastically, with their Snowlines starting high up the mountain, after a March-May heatwave marked by temperatures above 48C in northern India. An early June expedition in India's Himachal Pradesh found that the Chhota Shigri Glacier had lost much of its snow cover. "The highest temperature in over a century in March through May clearly had its impacts," said glaciologist Mohd Farooq Azam at the Indian Institute of Technology Indore.

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