Category Sea/Ocean

DOES ANTARCTICA HOLD MOST OF THE WORLD’S FRESH WATER?

The Antarctic ice cap contains about 91% of all the ice in the world and about 86% of all freshwater that occurs in the form of ice. But despite all this freshwater, Antarctica is considered one of the most arid places on Earth.

Antarctica is the highest, coldest, driest, and windiest of the world’s continents. It is also “tallest” in terms of average height above sea level. Nearly 99% of this land mass is covered with an ice cap with an average altitude of around 2 200 metres above sea level. The area of this vast continent – some 14 million square kilometres – doubles in the winter, when sea ice can stretch as much as 1000 km outwards from the coastline.

Most of the continent of Antarctica lies south of 70°S, although the Antarctic Peninsula stretches northward as far as 60°S. The continent is surrounded by the Southern Ocean, a circumpolar sea that isolates Antarctica from the other continents.

Most of Antarctica is covered with ice, but in many places mountain peaks (nunataks) stick up out of the ice. The Vinson Massif in West Antarctica, with an elevation of 5 140 m, is the highest peak in Antarctica. In addition to the nunataks, there are large ice-free regions called oases where the ice has retreated and where melting outstrips accumulation of new snow. Other areas, known as dry valleys, are free of ice because essentially no precipitation falls there.

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WHAT IS A BLOWHOLE?

Sometimes, the rocks along a coastline have a crevice or hole just above the low-tide mark. When the high tide rushes in, the crevice fills up with water, which tries to escape through this narrow hole. The build-up of pressure sprays out the water as an upward plume with a loud sound. This is a blowhole. Over time, a blowhole can create caves or even a pool of water near the coast.

When sea caves grow towards the land and upwards creating a vertical shaft that exposed on the surface, it results in a blowhole. Water often gushes out at the top part of the landform when waves move to the sea cave with significant force. The activities of the blowhole depend on the sea conditions as well as its geometry and that of the sea cave. A blowhole is characterized by an opening on the ground and a connection to an opening which interacts with the sea, mostly a cave.

Sea Caves are a common feature along the coasts and are formed through mechanical erosion of cliffs. Parts of weakness in the cliffs are weathered out by wave action thereby forming large cavities known as sea caves. These caves are regularly exposed to waves. Hydraulic pressure, built up by a succession of waves, eventually carves out a hole at the top of the cave to create an opening for water pressure to be expelled as a jet of spray. A blowhole can also be formed when lava flows make openings in the ground which extend towards the sea. The landform manifests as a crack or fissure once formed.

Credit: World Atlas

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When was the Aqua-Lung invented?

The aqualung invented in 1943 is the best and safest of all diving devices. Read on to know about the people behind the invention

About 200 years ago, divers used a device called a diving bell, which was lowered from a ship into the water. It was open at the bottom and received air from the surface through a hose. The air pressure kept the water out of the device. The diving bell gave way to the snorkel and diving suit.

However, the best and safest of all diving devices is the aqualung invented in 1943 by a French naval officer Jacques-Yves Cousteau and an engineer named Emile Gagnan. The aqualung is a portable diving apparatus, which consists of cylinders (tanks) of compressed air with a valve and mouthpiece. The valve adjusts air pressure automatically and supplies air as a diver needs it, so that air pressure inside the divers lungs matches the pressure of the water. Unlike previous devices, the aqualung was light and convenient and Lalung now part SCUBA millions Id every allowed the diver to move about freely.

The first aqualung was sold in 1946. The system is now part of modern SCUBA gear, with millions of units sold every year. Recreational scuba diving has become an international phenomenon.

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Helsinki to build world’s largest heat-pump

A 400-million Euro, 500-MW project to generate heat for the Finnish capital will use seawater from the Baltic even when the sea surface is frozen.

Seawater will be carried to the heat exchangers via a 17-km tunnel being bored from the Baltic seabed – where the temperature is a constant 2 degree C year round. Heat exchangers will transfer and concentrate the heat from the seawater-which is returned to the sea through a nine-km tunnel-to the district heating system where it will reach around 88 degree C.

Already home to the world’s largest heat pump, Helsinki is aiming to become carbon neutral by 2050, and the new pump alone is expected to provide up to 40% of the city’s heating requirements when it goes online in around 2029. A utility company currently provides around 8% of Helsinki’s heating through recovering heat from waste water and the excess from data centres and other buildings.

Frequency converter technology plays an essential role in heat pump product development. ABB’s frequency converters increase the efficiency of Oilon’s heat pumps in almost all of its sites in Helsinki. Frequency converter control can be used for the variable rotational speed control of a heat pump compressor.

“A heat pump must be able to handle different load and temperature conditions. Frequency converter control enables precise control and a large partial capacity range,” Martti Kukkola explains.

Frequency converter technology has Finnish roots – the first frequency converter developed by the engineers of Strömberg controlled the speed of metro trains in Helsinki. In ABB’s hands, the technology has evolved into an extensive frequency converter range, and ABB Finland is responsible for the technology’s global product development.

“Our reasons for choosing ABB are reliability, an extensive range, and equipment that is functional from a techno-economic perspective,” Kukkola says.

Using Oilon’s and ABB’s technologies, Helen has been able to provide its customers with more energy-efficient solutions to cover heating and cooling needs. Valuable heat is produced in a climate-friendly way as a by-product of cooling.

“As a technology leader, we want to be the trailblazer for energy efficiency, and by cooperating with partners, we can do more and have a greater influence in this area. It is valuable to be able to build a more sustainable future with Oilon and Helen by combining Finnish innovation expertise,” says Mika Männistö, Sales Director, ABB Motion Finland.

Energy-efficient frequency converters and motors offer substantial potential for cutting greenhouse gas emissions. ABB encourages all stakeholders to cooperate within the framework of the Energy Efficiency Movement to bring about a comprehensive reduction in energy consumption.

Credit : Energyefficiencymovement.com

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Shark attacks: what’s going on?

When one says conservation efforts to save a species have paid off, it usually means one thing a steady increase in the species population. And that’s good news. Recently though conservation efforts paying off had a slightly unexpected result. What is it? Come, let’s find out.

In summer, great white sharks move up the Atlantic coast of the U.S., towards New England. Their numbers normally hit the peak between August and October. But a few weeks ago, an unusual increase in human-shark encounters was evident along the U.S. East Coast, The reason? Experts believe it could ironically be due to the “conservation wins for vulnerable species”. There has been an increase in great white shark numbers, which experts think is the result of continued protection. And this likely led to increased human-shark encounters too.

An important factor in the shark number increase is the fact that the number of its main prey -the seal-has seen an uptick too due to protection. Scientists also believe that the increasing encounters could be “linked to the sharks bait fish-menhaden, also known as porgies or bunkers, recovering”. But they also warn that “it’s tricky to figure out how much of it is increasing populations moving around as a result of changing ocean conditions from climate change.”

Though there have been instances of sharks being portrayed in pop culture as blood-thirsty, that’s far from the truth. Studies have shown that sharks can mistake surfers or swimmers for their usual prey meaning many attacks could be the result of mistaken identity. Researchers say that if the number of beach-goers is anything to go by, there should be tens of thousands of shark attacks every year whereas the truth is that annual global deaths due to shark attack is five. When more sharks come close to land for feeding and more people go swimming, the encounters are likely to increase.

And with climate change experts expect “that the increase in ocean temperatures will gradually lengthen the season during which sharks are present in the northern United States”. This could mean increased chances of encounters in the future. Increased vigilance and self-awareness will go a long way in minimising the risk of attacks, feel experts.

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WHAT IS AMAZING ABOUT BLUE WHALES?

The blue whale, the largest known living animal on our planet, can be as large as an aeroplane and can weigh around 200 tonnes! A newborn blue whale is as big as a bus! What is interesting is that these giants mainly feed on tiny, shrimp- like sea animals called krill, which they filter out of the water in their mouths. They can eat around four tones of krill on a day!

1. Blue Whales Can Grow More Than 100 Feet Long

They are gigantic. Generally ranging in length from 80 to 100 feet (24 to 30 meters), the longest one ever recorded was a magnificent 108 feet (33 meters) long. That’s about as long as three school buses lined up end to end.

2. They Can Weigh as Much as 30 Elephants

The average weight for these gentle giants is 200,000 to 300,000 pounds (90,000 to 136,000 kilograms), or about 100 to 150 tons. Some can weigh as much as 441,000 pounds (200,000 kg), or 220 tons. For comparison, an adult African bush elephant weighs up to 6 tons, so it may take 30 or more elephants to equal the weight of one blue whale.

3. They Have Big Hearts

The blue whale’s heart is huge. It’s the largest heart in the animal kingdom, weighing about 400 pounds (180 kg) and roughly the size of a bumper car. As a blue whale dives to feed, its giant heart may only beat twice per minute.

4. They Have Big Tongues, Too

A blue whale’s tongue alone can weigh as much as some elephants.

5. They Have the Biggest Babies on Earth

Blue whale calves are the biggest babies on Earth, easily, and at birth already rank among the largest full-grown animals. They pop out at around 8,800 pounds (4,000 kg) with a length of some 26 feet (8 meters). They gain 200 pounds (90 kg) a day! Their growth rate is likely one of the fastest in the animal world, with a several billion-fold increase in tissue in the 18 months from conception to weaning.

6. They’re Unusually Loud

Blue whales, in fact, are the loudest animals on the planet. A jet engine registers at 140 decibels; the call of a blue whale reaches 188. Their language of pulses, groans, and moans can be heard by others up to 1,000 miles (1,600 kilometers) away.

7. They Eat a Lot of Krill

Blue whales feast on krill; their stomachs can hold 2,200 pounds (1,000 kg) of the tiny crustaceans at a time. They require almost 9,000 pounds (4,000 kg) of the little guys a day, and around 40 million krill daily during the summer feeding season.

8. They’re Pretty Fast

They travel a lot, spending summers feeding in polar regions and making the long trip to the equator as winter comes along. While they have a cruising speed of 5 mph (8 kph), they can accelerate up to 20 mph (32 kph) when needed.

9. They Have Long Life Spans

Blue whales are among the planet’s longest-lived animals. Kind of like counting tree rings, scientists count layers of wax in the ears and can determine a ballpark age. The oldest blue whale they’ve discovered this way was calculated to be around 100 years old, though the average life is thought to last around 80 to 90 years.

10. They Once Were Abundant

Before whalers discovered the treasure trove of oil that a blue whale could provide, the species was plentiful. But with the advent of 20th-century whaling fleets, their population plummeted until finally receiving worldwide protection in 1967. From 1904 to 1967, more than 350,000 blue whales were killed in the Southern Hemisphere, according to the World Wildlife Fund. In 1931, during the heyday of whaling, an astounding 29,000 blue whales were killed in a single season.

11. Their Future Remains Uncertain

While commercial whaling is no longer a threat, recovery has been slow and new threats plague blue whales, like ship strikes and the impact of climate change. There is one population of around 2,000 blue whales off the coast of California, but all told there are only around 10,000 to 25,000 individuals left. The International Union for Conservation of Nature lists the species as endangered. Hopefully with time, the planet’s largest gentle giants will again roam the seas aplenty.

Save the Blue Whale

  • Look for seafood certified by the Marine Stewardship Council (MSC), which can help reduce the prevalence of fishing gear known to entangle blue whales.
  • If you ever see a blue whale, keep your distance — for its safety and yours.
  • Watch your speed and keep a sharp lookout if you’re ever on a watercraft in potential blue whale habitat. Boat collisions can seriously injure blue whales.

Credit :  Treehugger.com

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