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At 8:29 a.m. on Nov. 30, part of the rock slab underneath the water 7 miles north of Anchorage, Alaska, shifted, causing a magnitude 7 earthquake. As Anchorage was preparing for the day, the quake ripped apart roads, shattered windows and ruptured water and gas lines in and around the city. While officials are still assessing the damage, the biggest impacts appear to be to infrastructure—there were no reports of deaths caused by the quake.

The response to such an event is extensive and wide-ranging: Across the globe, seismometers—instruments that measure tiny ground movements—recorded the earthquake’s signals. Scientists at the Alaska Earthquake Center and elsewhere started piecing together what happened and monitoring the hundreds of aftershocks that followed. Federal officials briefly issued a warning for a tsunami, until the danger passed. Later in the day, the Federal Emergency Management Agency helped coordinate disaster relief efforts, such as opening up shelters for Anchorage residents displaced from their homes.

In some areas, the earthquake caused the ground to liquefy and flow out from underneath roadways, collapsing the pavement into jagged chunks. That process, called liquefaction, happens when a quake shakes earth saturated with groundwater and made of a less-rigid material than solid rock, like sand or mud.

“It’s very important for us to recognize what areas are prone to liquefaction so that we can either avoid building there, or engineer around it,” said Jackie Caplan-Auerbach, a geology professor at Western Washington University.

A federal program called the National Earthquake Hazards Reduction Program supports all of those activities and more. Last week, a bill reauthorizing the program—bolstering support for it in the future—landed on President Donald Trump’s desk after both the Senate and the House passed it.

The bill was co-sponsored by several Western lawmakers, including Sens. Lisa Murkowski, R-Alaska, and Dianne Feinstein, D-Calif. Congress’ explicit directive to fund the earthquake program expired in 2009; since then, lawmakers have been allocating money for it in a piecemeal fashion, year-by-year. The new bill authorizes Congress to spend millions of dollars over the next five years, including at least $30 million per year to a U.S. Geological Survey program responsible for monitoring earthquakes and developing an earthquake early warning system so sensitive that it could issue alerts to communities several seconds before they’re hit by strong shaking. The USGS is rolling out a prototype of the alert system this year, limited to California, Oregon and Washington.

The legislation also includes a few updates to the 1977 law that created the national earthquake program. One of the most significant revisions, said Michael West, the director of the Alaska Earthquake Center, is the explicit inclusion of tsunamis in federal earthquake assessments. That’s important, because in Alaska and the Pacific Northwest, tsunamis can be the most deadly impact of an earthquake: Of the 139 people who died because of a magnitude 9.2 earthquake in Alaska in 1964, 124 were killed by tsunamis.

“If you’re leaving out the tsunami risk, you are short-selling those areas,” West said.

The relatively small impact of Friday’s earthquake stems from a history of preparation: Experts praised Anchorage’s building codes, which were bolstered after the 1964 quake, for the lack of widespread building collapse. Still, the region sustained extensive damage to infrastructure and roads, which the USGS estimates could cost tens to hundreds of millions of dollars to fix.

Alaska will still be dealing with the aftermath of the quake—and preparing for the next one—long after the attention of the nation and its lawmakers has moved on.

“That’s where legislation helps,” West said. “It says, ‘Hey, let’s keep this on the radar so we’re ready, or as prepared as we can be.’”

Emily Benson is an assistant editor at High Country News, where this piece first appeared.

Published in National/International

Aspen trees are the rock stars of the tree world. They have a bold fashion sense, gilding the mountains in gold each fall. And they engage in risky behavior: In the competitive world of plant biology, their strategy is to grow fast and die young. Juniper trees, which grow slowly, invest much of their carbon in building strong vascular tissue; aspen trees instead put carbon toward growing tall quickly.

Yet the two trees adopt the same strategy when drought hits: Unlike pines, they leave their stomata open. Those tiny pores on their leaves allow the trees to take up carbon dioxide from the atmosphere and photosynthesize. But the atmosphere demands water in return, which escapes through the tree's stomata. During drought, the process creates extra tension in the plant's tissue, since the trees have less water to give, and the parched atmosphere is especially thirsty.

This is when the juniper's investments in building tough tissue pays off: The tubes that transport water through the tree can withstand an increase in tension. The Aspen tree, on the other hand, becomes vulnerable. Their tubes are more likely to collapse, which can eventually lead to the tree's death.

A few years ago, Bill Anderegg, a forest who is now an assistant professor at the University of Utah, figured out that this was what was killing aspen trees in his native Colorado. (Around 2004, aspen trees throughout the Rocky Mountains began mysteriously dying in droves, a phenomenon that was dubbed "sudden aspen decline.") But he noticed something else curious about their pattern of death: There seemed to be a lag between the drought and its consequences. Tree growth would slow for a few years, but they often wouldn't start to die until three to eight years after the drought.

"There was an interesting paradox of trees being stressed and dying from drought in completely wet soils," Anderegg says. "Which prompted me to ask the question: How widespread are these legacy effects?"

It turned out they were quite widespread, according to the results of a study Anderegg recently authored in the journal Science. Using data from a global tree ring archive, Anderegg measured tree growth following severe drought at 1,338 sites, primarily in the Northern Hemisphere and outside the tropics. Growth is a good proxy for forest health, Anderegg explains, and it's also the primary way trees store carbon. That's important, because globally, forests take up about a quarter of anthropogenic carbon emissions. Their continued ability to sequester carbon at that level is critical to blunting the most severe effects of climate change.

With a few exceptions, tree growth slowed for two to four years after severe drought, with the most enduring effects appearing in arid environments—another indication of the troubles Southwestern forests are likely to face as the climate warms.

"It does seem like species that took more risks during drought seemed to recover more slowly," he says, like aspen, which don't close their stomata and conserve water. "Which does indicate that there's some role of this damage to their hydraulic systems that could slow their growth in subsequent years."

Scientific models of the global carbon cycle—which are important for projecting climate change—don't account for this slow-down in growth. "The models assume there is no lag, so as soon as climate is better, so is growth," says Nate McDowell, who researches the physiology of tree death at Los Alamos National Lab in New Mexico. That means that models may overestimate the ability of ecosystems to store carbon—and underestimate the severity of future climate change.

If droughts do become more frequent and severe, Anderegg says, as climate models predict, "this suggests that more forests are going to spend more and more of their time recovering, and become less good at taking up carbon." Anderegg estimates that in Southwestern forests, the lag could amount to a 3 percent reduction in their carbon storage over a century. That may not sound like much, but when it comes to squirreling away the emissions we stubbornly keep spewing, we need all the help we can get.

Plus, the meaningfulness of such numbers is a matter of scale, notes Adrian Das, a forest ecologist with the U.S. Geological Survey in the Southern Sierra Nevada. While we don't know what the precise effect of that reduced carbon storage might be, locally or globally, "these changes can translate into really large absolute numbers," he says. "Three percent is not very much if it’s five trees. It means something different if it’s thousands of trees."

Cally Carswell is a contributing editor to High Country News, where this story originally appeared.

Published in Environment

Amphibians are vanishing at an alarming rate—even from areas we think of as pristine and protected. California’s Sierra Nevada range is a prime example of this global problem: Five out of seven amphibian species there are threatened. Researchers are still trying to pinpoint exactly why ponds that once held mountain yellow-legged frogs or California red-legged frogs are now devoid of amphibians.

In a new study, a U.S. Geological Survey group focusing on how pesticides affect amphibians tested common Pacific chorus frogs and their habitats, including Yosemite National Park and Giant Sequoia National Monument, for around 100 agricultural chemicals. Even though researchers have looked at pesticides in Sierra Nevada amphibians for years, the new study’s most commonly detected chemicals—two fungicides and one herbicide—have never been found in amphibians until now.

“As pesticide use changes, our studies have to evolve as well,” says Kelly Smalling, a USGS hydrology and chemistry researcher, and the lead author on the study. As new pesticides are approved, it's difficult to keep pace with where they end up in the environment, so the USGS group tested for a large batch of them in seven remote locations. “That’s how we stumbled across the fungicides.”

In 2005, the U.S. Environmental Protection Agency approved the two fungicides found in the new study, pyraclostrobin and tebuconazole, to combat a new soybean rust—the spores of which may have landed in the U.S. from South America during the 2004 hurricane season.

Pesticides, and diseases like the chytrid fungus, plus habitat loss and climate change, are among the possible reasons amphibians are blinking out in pristine areas. Earlier studies established that pesticides get into Sierra Nevada snow, water and sediments by wafting from the Central Valley, one of the nation’s most intensive agricultural regions. Frogs downwind of the valley are declining more rapidly than coastal or northern frogs.

Researchers also found in previous studies that pesticides commonly applied in the Central Valley—chlorpyrifos,and DDT-like endosulfan (which is being phased out)—showed upin declining populations of Sierra Nevada Pacific chorus frogs, and also in imperiled yellow-legged frogs. Smalling’s study only looked at Pacific chorus frogs, because they are not threatened, and so the population wouldn’t be harmed by a few sampling causalities. Yet the work still may point the way to research that could help narrow down what’s harming more rapidly declining species like yellow-legged frogs.

The next step, according to Smalling, is figuring out how the fungicides could affect, or kill, amphibians. That means a lot of difficult laboratory work, partly because every frog species may respond to pesticides differently.

As for how pathogens like the chytrid fungus might be interacting with pesticides to kill frogs, that remains a mystery.

“I think it’s quite likely that there is an interaction between pesticides and other stressors,” says Gary Fellers, a wildlife biologist on the study who has worked on amphibian declines since the ’90s.

Fellers, who recently retired from the USGS, grew up backpacking in Yosemite, where he still does field work. “I know of frog populations that are entirely gone now,” he says. “I’m incredibly anxious to find what’s causing these declines before we lose entire species.”

Sarah Jane Keller is the editorial fellow at High Country News, the site from which this was cross-posted. The author is solely responsible for the content.

Published in Environment