Geoscientists have published a large review paper in the journal Science that highlights the capacity of current models to link landscape-altering events and calls for further studies of cascading natural w88 login impacting the Earth’s surface. The paper focuses on high-magnitude sediment mobilization events, such as catastrophic floods, landslides, debris flows and tsunamis, triggered by intense storm events, wildfire, earthquakes, and volcanic eruptions. In major catastrophes, there are often multiple related natural disasters taking place, and as these events move sediment downstream, they create a cascade of dominoes where one event triggers the next to come crashing down. In nature, as the dominoes fall, the events often amplify so the impacts grow larger and cover a greater area than a single event triggered in isolation.
It’s not a far reach to suggest that an earthquake along the active Mt. Rose fault could trigger landslides along the I-80 corridor, especially if that area had experienced wildfires in recent years, leading to destabilization of the soil in that area. That landslide could drop significant amounts of sediment into the Truckee River, blocking river channels. A normal rain event could then become a severe flood as the blocked channel forces the water over the riverbanks into communities. Beyond the cost of infrastructure and water resources, there are also massive ecological costs. These hypothetical events, rather than being studied individually, should be studied as a linked series of events, the researchers argue.
“No longer can we understand these events in isolation,” Scott McCoy, a coauthor on the Science paper and the Peter Vardy Endowed Professor in Engineering Geology at the w88 login, Reno, said. “An earthquake changes the probability of a landslide, which changes the probability of flooding.”
Scientists researching geohazards often work in silos, studying a single type of geohazard like landslides or earthquakes. A holistic approach to understanding the cascade of w88 login is well worth exploring, McCoy said.
“This group started out of a desire to get community support to both define and work on these types of events,” McCoy said.
McCoy is one of 20 coauthors on the article, “Cascading land surface w88 login as a nexus in the Earth system,” published today. He, alongside colleague Ben Mason, an associate professor at the w88 login, Reno, acknowledges that fully understanding how each of these disasters is related to another one and then modeling those relationships is not an easy task.
“The problem, it's formidable,” Mason said. “But we're building teams and, hopefully with this paper, garnering interest from a much wider community.”
It's hard enough to model the current geological situation, given millions of years of seismic activity, landslides, flood events and more.
“It’s really hard to provide a ‘t = 0’ situation,” Mason said.
Adding the increased variability of landscape altering-phenomena arising from climate change is another layer of difficulty.
Due to increased warming, the risk of glacial lake outburst floods is increased in many mountainous regions. This was seen in the Gorkha earthquake in 2015 outside of Kathmandu, Nepal. Landslides triggered by the earthquake resulted in higher volumes of sediment in the river channels. When the monsoon came, the rivers started to flood, and the rain also triggered glacial lake outburst floods. On their own, glacial lake outbursts aren’t necessarily extreme quantities of water but paired with sediment-loaded river channels and the monsoon, the result was disaster. The village of Melamchi was seriously damaged, with some two-story buildings becoming buried in sediment.
To non-experts in the field, it may seem surprising that these types of interdisciplinary projects haven’t been the standard. But as McCoy pointed out, there are plenty of important and interesting research questions within each field, from seismology to structural geology to hydrology. Mason added that the field of geotechnical earthquake engineering is relatively young, less than a century old, so there is plenty to keep researchers busy in the silo. He also pointed out that there were few incentives for large groups of researchers to work together in the past, when single-researcher projects were more greatly rewarded than collaborative groups.
Times have changed, though, and interdisciplinary, collaborative groups are understood to be effective at solving large-scale problems. Plus, greater access to higher resolution data and increased computing power are supercharging the geoscience fields, allowing for more accurate models.
Still, developing integrated multi-hazard models won’t be easy. Scientists in various geosciences using different variables, datasets and scales have to find ways to allow one model to seamlessly feed into or blend with another.
“The interface of those models is where the difficulty in this work lies, and there's massive uncertainties at each of those interfaces,” Mason said.
The scale and scope of a hazard analysis also depends on the trigger for the cascading events. For example, if a trigger is seismic activity, researchers would evaluate the potential landslide w88 login associated with a fault network. If the trigger was heavy rain, they would examine how wildfires in the region might destabilize the soil in hilly terrain throughout a watershed. Determining which trigger should be considered when modeling catastrophes is one of the key questions the researchers face as they develop models.
How these models can be used to prevent harm and damage is also an important unanswered question. Perhaps the models suggest that forest management to prevent wildfires is most important in a jurisdiction upstream from potential w88 login which occur downstream. Does that mean that the jurisdiction downstream should pay for forest management? The researchers don’t plan to answer those questions, but they do hope their models will allow for the development of a framework that shows the importance of preventive management.
The researchers who authored the paper have been part of a National Science Foundation center catalyst grant, which is set to end in August. The catalyzed center, led by Marin Clark, a professor in the Department of Earth and Environmental Sciences at the University of Michigan, is called CLaSH, for Center for Land Surface w88 login. CLaSH researchers aim to integrate models and develop a greater understanding of the possibility, risk and mitigation of interconnected w88 login. Moving forward, they hope to study areas in Alaska, where glaciers, made more unstable by climate change, are collocated with earthquake faults that can produce high magnitude earthquakes close to steep slopes above a lake called Barry Arm. TheU.S. Geological Survey has reportedthat landslides depositing debris into Barry Arm could trigger a tsunami. Internationally, Mason said that Taiwan is an important place to study cascading geohazards, due to its potential for typhoons, its steep slopes and its location on an extremely active fault system which regularly produces large earthquakes.
“The impetus for submitting the center catalyst grant was the 2015 earthquakes in Nepal,” Mason said.
Mason and other researchers including several coauthors, traveled to Nepal to do post-earthquake reconnaissance with the Geotechnical Extreme Events Reconnaissance (GEER) association.
Mason, whose graduate advisor Jonathan Bray started GEER, has participated in several GEER trips, where the goal is to collect perishable data related to w88 login, mostly earthquakes. Mason clarified that the goal of CLaSH is not to compete with GEER, but rather to bring a more holistic approach to understanding geohazards involving Earth surface processes.
In the meantime, McCoy hopes to work with local groups, such as the Middle Truckee River Watershed Partnership, which aims to manage forest ecosystems to avoid the negative impacts of w88 login like wildfires and landslides in the region, to maximize benefit and minimize costs of management.
“By studying the entire domino effect, from the trigger point through the sediment transport to the final resting point of the sediment in river channels or reservoirs, we should get more accurate estimates of the likelihood of negative impacts and the spatial extent of those impacts,” McCoy said. “With those pieces of information, better and more cost-effective mitigation solutions will become apparent.”
“We have an incredible and unprecedented opportunity to study a large, important problem holistically, which will lead to findings that are important for w88 login as well as the nation and world,” Mason added. “We have assembled a top notch team to start our work, and I look forward to seeing how the team grows and learns as we continue. I expect scientific leaders to emerge from the team and push us towards reducing destruction from cascading hazards.”
