Direction: Read the given passage carefully and answer the questions that follow. Certain word (s) are printed in bold to help you locate them while answering some of these.
Genghis Khan got his dying wish: despite attempts by archaeologists and scientists to find the Mongolian ruler’s final resting place, the location remains a secret 800 years after his death. The search for his tomb, though, has inspired an innovative project that could help protect polar bears.
“I randomly tuned into the radio one night and heard an expert talking about the use of synthetic aperture radar [SAR] to look for Genghis Khan’s tomb,” says a researcher involved in the project. “They were using SAR to penetrate layers of forest canopy in upper Mongolia, looking for the ruins of a burial structure.”
Talking to engineers, the researcher learnt that SAR is used by the military to detect enemy camps, tanks and vehicles hidden beneath camouflage and is being studied as a potential tool for finding avalanche survivors. He and his team had been looking for a technology to detect polar bear dens. “It was very serendipitous that I heard that broadcast,” he says.
Successful pilot tests using SAR to find simulated polar bear dens took place in Alaska’s Prudhoe Bay in 2014 and 2015. The project was resurrected with trials in March 2021 on a snowy mountain plateau in Utah’s Manti-La Sal national forest. A SAR device was fitted to a Cessna O-2A Skymaster that flew 3,000ft (900 metres) over researchers and students digging dens a metre under the snow. With a lack of polar bears in Utah, students crawled inside to act as targets, or laid out simulated bears made from cardboard and tinfoil.
Building dens is a critical period for polar bears. For months, vulnerable cubs rely on their mother’s milk and the safety of the den to survive. As polar bears are driven further inland by receding sea ice, denning areas and oil and gas activity increasingly overlap. Disturbances can push fearful mothers to abandon their dens. The chances of survival for _____________________________________.
With fewer than 26,000 polar bears thought to be left globally and an estimated decline of 40% in some populations, such as the southern Beaufort Sea, every den and bear counts.
SAR detects objects by sending pulses of radio waves; sensors pick up the echo or “bounce” to map an area. The aim is to find the right frequency, a sweet spot, that can penetrate snow but still detect a bear.
Getting reliable data on denning sites is vital. “The Arctic national wildlife refuge is the perfect example,” says a researcher. “Industry wants to go in and pump oil. If we have a tool that definitively says exactly where polar bear dens are, that means keeping people away from those places. If we want bears, we need baby bears, so we’ve got to protect those dens.”