Snow in the Wasatch Mountains above Salt Lake City had more dust deposited (沉积) on it in2022 than in any year since observations began in 2009. The dust deposits caused snow to disappear 17 days earlier than before.

“Earlier, faster snow melt may change the water supply for the 1.2 million people living there, as well as ecosystems downstream,” says McKenzie Skiles, a snow hydrologist at the University of Utah. “It also affects the region’s ski areas, which contribute more than $1.5 billion per year to the local economy.”

In dry parts of the western America, snow acts as a natural reservoir (蓄水池). More than half the water in Salt Lake City comes from four streams that drain snow out of the Wasatch Mountains. But current forecasting tools don’t account for the impact of dust, which absorbs sunlight, speeding up snow melt. That means people can’t accurately predict when snow runoffs (径流) will happen so they can use water efficiently.

As a skier, Skiles noticed the mountains near Salt Lake City looked especially dirty in 2022. So she and her colleagues investigated whether the increase in dust was related to constant years of record-low water.

They collected snow samples there and found that storms deposited substantial amounts of dust 16 times during the 2022 snow melt season. After calculating where the dust came from during each storm based on wind direction and atmospheric conditions, they found that Great Salt Lake contributed nearly a quarter of the total dust to the study site. It also released the most dust relative to the lake’s exposed surface area. “This was surprising,” Skiles says, “because the Great Salt Lake’s dry lakebed is tiny compared with the exposed surfaces of neighboring dust sources.”

“Utah will be drier because earlier snow melt causes the landscape to dry out faster,”Skiles explains. As Great Salt Lake gets smaller and deposits more dust on the mountains, there’s less water available to refill the lake during the summer, which in turn exposes a larger dust source.

Some of the most attractive pictures to come out of the Alaska earthquake are the photos that show slope (斜坡）failures, in which parts of formerly solid hills caved in，tore or let loose. And if there happened to be a road or building on top of the slopes that failed，the result was horrible.

Slopes can fail without earthquakes, as the result of pouring rain qr w：eathering. But the shaking caused by a quake — particularly a large one like what occurred near Anchorage on Friday — can either speed up the process or create entirely new failures that wouldn't have otherwise happened.

Several slope failures were documented in the Anchorage area in the hours after the earthquake Friday, the most interesting of which was on Vine Road southwest of Wasilla. It’s as if someone came along with a large destroying ball and dropped it on Vine Road, which wrinkled like a broken egg.

Scientists seemed surprised at how many slope failures occurred as a result of the 7.0-magnitude (震级）quake. The center of the quake was deep, at 27 miles below the surface — a key reason why the damage in Anchorage was relatively light. Such an earthquake would be expected to produce shaking over a large area, but probably with reasonably modest top ground accelerations, Friday’s earthquake would certainly be felt, but the surface of Earth wouldn't be moving badly enough to produce widespread landslides.   

Photos from Alaska show a lot of lateral (横向的）spread, in which the ground tears open. Whatever is on top of the ground at the place it tears in half is also torn in half afterwards, like highways or buildings. The buildings surrounding the spread are also at risk of damage because of the force of the ground spreading out away from the tear. There’s also documentation of block spread，in which part of the ground breaks off a hill and slides away mostly perfect.

Several security guards of residential compounds in Beijing and workers were seen shoveling snow and some parked vehicles were covered by thick overnight snow. The first snowfall of winter arrived in Beijing early Monday, covering the Chinese capital with a mantle (披风) of white overnight and plunging (使……下降) the city into freezing temperatures, with even colder weather coming this week in northern China.

Snowfall reached 5.8 mm on average by early Monday, with the highest snowfall of 10.2 mm recorded in Fangshan district, Beijing Meteorological (气象的) Service data showed. Beijing typically sees its first snow of the season between late November and February, or even none at all. More snowfall is expected this week, with temperatures seen further sliding to as low as -20°Celsius. The Chinese capital last saw such similarly extremely cold weather on Jan. 7, 2021, when the temperature dropped to -19.6℃.

The cold snap (寒潮) in Beijing this week, compared with the autumn-like conditions a week ago, mirrored the sharp swings in temperatures recently. In October, Beijing experienced one of its warmest Octobers in decades in a year of weather extremes.

On Monday, the government warned of road icing in large parts of the city of nearly 22 million, with authorities shutting some expressways or partially closing sections. By 10 a. m. local time, 62 out of a few hundred flights had been cancelled at the Beijing Capital Airport. Railway authorities enforced speed limits on lines connecting Beijing and Guangzhou in southern China, causing delays in some passenger trains. By 7 a. m. Monday, more than 180 bus routes in Beijing had been suspended.

The official Beijing Daily reported that vegetable stocks were enough, hitting this year’s highest daily market volume of 23,800 tons, as merchants stocked up (备货) ahead of time. Huang, a Beijing resident working in the internet sector, said the snow in Beijing came early. “Normally, it doesn’t snow until the Spring Festival,” Huang said, referring to the start of the Lunar New Year, which typically falls in January or February.