Planetary scientist and glaciologist Jeff Kargel was thinking about climate change on Earth without enough consideration for irreversible changes––he wants you to know what he now understands. “My confession is that the signs and the models were in place by 2005, but I was still thinking in gradualistic terms. I was not thinking about abruptly changing behaviors of the gigantic currents of the Earth’s atmosphere and oceans. In 2005, I thought that climate change was gradual and readily manageable. I was wrong. I didn’t consider nonlinear effects— the tipping points— that climate change would have on individual components of the Earth system.”
Read the full admission by Jeff Kargel on GlacierHub here.
Province in Turkey Hit by Multiple Avalanches
Turkey’s Van Province suffered a series of devastating natural disasters the first week of February, with two avalanches occurring within 24 hours of each other. The avalanches were triggered in the same area near a highway outside of the town of Bahcesaray. The first avalanche struck on February 4 and the second followed on February 5. The Turkish Natural Disaster and Crisis Directorate announced the following day that the death toll had climbed to 41 with nearly 100 others injured.
‘The Most Prestigious’ Environment Prize In History
In October 2019, GlacierHub reported on Prince William and Duchess Catherine’s visit to a remote Pakistani village, Bumburet, in the Hindu Kush to view the Chiatibo Glacier––the first time the couple had seen a melting glacier. Less than three months later, on the eve of the New Year 2020, the couple announced The Earthshot Prize, which is being called “the most prestigious environment prize in history.”
Read the story by Ecowatch here and see the short clip, narrated by David Attenborough, below.
I am a glaciologist and planetary scientist, now at the Planetary Science Institute, formerly at the University of Arizona and US Geological Survey. I cofounded, then directed Global Land Ice Measurements from Space. My work involves remote sensing and field studies of glaciers, glacial lakes, and landslides. I apply science to human concerns when earthquakes hit mountains, glacial lakes burst, landslides and avalanches dam rivers, or when mountain disasters destroy oil pipelines, highways, villages and military bases.
My earliest University studies in geology taught me about natural coal ages and ice ages. I became concerned about human-caused climate change in the 1980s when the scientific community’s alarm amped up about industrial emissions of carbon dioxide and other heat-trapping gases. The basic physics is not complex. Human-caused global warming was predicted in the 1890s by Svante Arrhenius and Thomas Chrowder Chamberlin. They recognized that fluctuations in atmospheric carbon dioxide and water vapor explain the ice ages and interglacials, and that industrial emissions of carbon dioxide eventually would alter Earth’s climate.
If not for greenhouse gases, the Earth would be gripped by a permanent global ice age. But if too much of these gases are added rapidly, then climate change is injurious. Venus, where surface temperatures are near 750 degrees F, has an extreme “super-greenhouse.” Mars, on the other hand, has so little greenhouse gas that, together with its greater distance from the Sun, keeps it more frigid than Antarctica.
Global climate is normally regulated by geology and Earth’s rotational wobble, solar physics, and Jupiter’s gravitational tug on our planet’s orbit. The drift of continents and emissions of volcanic gases can cause the climate balance to be tipped toward a full ice age; or to a full hot house, where rain wears down the continents and mountains are partly replaced by global swamps— organic accumulations then eventually form coal, oil, and natural gas. These swings happen naturally, primarily slowly, and life adapts accordingly.
Civilization has grown during a relatively stable climate. Small natural climate swings have caused famines, desertification, and spread of grasslands, affecting nomadic, agricultural, and urban societies. Natural climate changes have caused civilizations to collapse, including a 13th century mega-drought induced failure of the Anasazi and other Pre-European Native cultures in and near my state of Arizona.
In 2004— a US Presidential election year— my agency (USGS) caved in to the climate change denialism of President George W. Bush, a former oilman, who apparently didn’t want understanding of greenhouse gases and a warming planet to spread among the public. Public communications about the science of glaciers and climate change were stymied. I resigned my civil servant position so that nobody could dictate my public communications. Never one to tolerate either climate change exaggeration or climate change obfuscation, I did not participate in the minimization and hiding of evidence for climate change. I always thought that the modern global economy can adapt and mitigate 21st century impacts from a couple degrees of human-caused climate warming. (And we can if we are smart about it.)
Around 2005, I started paying attention to the continuing work by Dr. Jennifer Francis (then at Rutgers University, now Woods Hole Research Center). The melting of Arctic sea ice, predicted in 1981 by Jim Hansen and colleagues, already was underway. Francis had linked the fast-warming Arctic and melting sea ice to shifts in the behavior of Earth’s jet streams — the great rivers of stratospheric air that guide storms, speed eastward-bound airliners, and slow westward flights. The now familiar, dreaded, related winter weather phenomena known as snowmaggedons, polar vortex disruptions, and bomb cyclones also had begun, and extreme drought and heat waves in both summer and winter were being reinforced by slowly moving or stationary and wildly meandering jet streams— the kind of extreme weather that Francis with colleagues has explained, other climatologists have also supported, and which the public is grasping in terms of consequences.
I was not thinking about abruptly changing behaviors of the gigantic currents of the Earth’s atmosphere and oceans. In 2005, I thought that climate change was gradual and readily manageable. I was wrong. I didn’t consider nonlinear effects— the tipping points— that climate change would have on individual components of the Earth system.
Hurricane Katrina hit also in 2005, and since then a succession of Category 4 and 5 hurricanes have struck North America and Asia, and year-upon-year of ever-warmer, record-warm conditions have hit worldwide. The climate and extreme weather news just in 2019 and 2020 is alarming not just to scientists but to a wider public. Jennifer Francis is onto something big, as she has connected climate change to extreme weather with a climatological understanding as almost nobody else had previously done. Forest fires have raged seasonally on six continentsat levels that previously were uncommon or historically unprecedented. Wildfires have become an increasingly frequent feature of the past two decades’ evening news in California, Alaska, Australia, Scandinavia, and Siberia. Wildfire links to climate change are understood scientifically and were predictedand are also understood by the public.
As if the changing atmospheric circulation isn’t enough, there is increasing evidence that some ocean currents are changing from historic behavior. In 2014 I attributed part of the variability in glacier behavior to regional adjustments of ocean currents to shifting global climate. Overall, glaciers started melting 150 years ago in response to a modest natural warming episode earlier in the 19th century, and since the 1990s the melting binge has speeded dramatically. This behavior recently extends to the Greenland ice sheetand parts of Antarctica.
A finely tuned Earth system from a century ago has become more disrupted than at any time in human civilization, by some measures more than since modern humans (Homo sapiens) have lived, and by other measures more than going back halfway to the age of dinosaurs. Carbon dioxide levels assure that much more change is pent up and is coming our way.
My confession is that the signs and the models were in place by 2005, but I was still thinking in gradualistic terms. I was not thinking about abruptly changing behaviors of the gigantic currents of the Earth’s atmosphere and oceans. In 2005, I thought that climate change was gradual and readily manageable. I was wrong. I didn’t consider nonlinear effects— the tipping points— that climate change would have on individual components of the Earth system. My change of perspective stemmed partly from my own research into melting glaciers and the roles of exceptional heat or rain in triggering glacier surges, ice avalanches, and glacial lake outbursts, and that these processes involve climate-tipping points and glaciological tipping points. But then there were record breaking hot summers and drought in my home state of Arizona, and record breaking wildfires nearby in California. Those are just the impacts I personally deal with every year. Globally there are so many 500-year floods, 500-year droughts, unprecedented firestorms, so many $10 billion and $100 billion hurricanes that we forget their names, and bizarre weather patterns that have no place in history. At some point, we run out of excuses that it’s just an anomaly for this, and a different anomaly for that. The recognition hits: the data on greenhouse gases and global warming connect to the climate models, and the models connect to the observed rise in extreme weather, and lately, to burning koalas and kangaroos.
are by nature cautious in our technical work. However, it can become
misleading, even unethical, to leave the public with what to them is a
confusing concept of statistical uncertainties and error bars and confidence
limits; our language must not obscure the underlying understanding and urgency
that the scientific community has about what is happening and why and what is
will not turn into a Venus, but my planetary science mind definitely sees how
rain forests turn to deserts, how nations lose their food supplies, and wars
erupt. The climate system is in upheaval, and global climate change has global
economic reach of course. As a scientist, I see that the gap between climate models
and extreme weather observations is not yet closed at the local and regional
levels. It is locally and regionally where the most serious impacts of climate
change nonlinearities— the tipping points— are being felt. In politics, as a
famous American House Speaker once said, “All politics is local.” In climate,
we ought to take the same approach to inform public understanding. People care
about burning koalas, but they will vote on climate change when they see the
Fifteen years after my enlightenment, we have more than a crisis, arguably not yet an apocalypse. The planet has been through worse. But humanity, aside maybe from Homo robustus, has never witnessed such drastic changes to our environment, a period now known to geologists as the Anthropocene. Civilization is slowly preparing, but not on a schedule to match climate change’s impacts on people, dollars, and nature.
Scientists, economists, engineers, and business people— and many politicians— know what should be done and how to do it. We can affordably transform our economy to move off fossil fuels. Most nations want to do this. Roadblocks against international climate change agreements and national policy initiatives are erected by crafty saboteurs, who use “manufactured doubt” about climate change. They implement myriad infrastructural supports and subsidies for 20th century technologies to keep the world hooked on fossil fuels.
It might be too late. I am not of a view that is already clearly too late. Too late for what? The worst? No, it is not too late to make things worse. After a depressing January, my almost irrepressable optimism is reasserting that we can chart and follow a better course. Politicians will come onboard, pressured by public opinion and climate change activists such as Greta Thunberg. Maybe this year’s record-breaking, nature-killing, sea-to-sea-to-sea bushfires across Australiawill awaken politicians there. It’s something everywhere, every year.
Though there are hopeful political glimmers in China, the U.S. and elsewhere, the corporate world may be issuing a mandate for the needed changes. Though still attracting climate activists’ skepticism, a rather believable and substantive action plan has been announced by the $7 trillion BlackRock investments— the world’s largest investment group. Climate activists’ pressure is needed to assure follow through. Around the world, no matter what the economic system, people— powerful people especially— respond to where money flows. Furthermore, the rich and powerful have children, too. Maybe the message is getting across.
On Saturday, September 9, part of the Trift glacier in the Swiss Alps broke off and crashed into a glacier below it. About 220 people of Saas-Grund, a small nearby ski town, evacuated the area as a precaution, said local police spokesman Simon Bumann. The collapsed piece measured approximately 500,000 cubic meters. Local authorities who had been surveilling the glacier found that the glacier’s tongue, a long and narrow extension of ice, was moving at about 130 centimeters per day, according to the Valais canton police.
It was during the night that the glacier’s movement began to increase. Eventually, more than two-thirds of the glacier’s front edge broke off on Sunday morning, but the debris that hit the glacier below didn’t reach the surrounding inhabited areas. Authorities feared that the broken piece could have triggered an ice avalanche, potentially impacting the town. In August, eight hikers were buried when a rockfall triggered an avalanche in Bondo, Switzerland. The avalanche in Bondo moved about four million cubic meters of mud and debris, which is the equivalent of 4,000 houses, about 500 meters, according to the regional natural hazards office.
Since the evacuation ended in Saas-Grund, residents have been able to return to their homes, and local roads around the glacier have reopened. As a precaution, the area underneath the glacier, including hiking trails, remains closed to walkers.
Thanks to Martin Funk, a glaciologist at the technology institute ETH Zurich, the surrounding villages were able to evacuate in time before any damage had been done. Funk had recommended that an expensive radar system be reinstalled just three days prior to the incident to keep an eye on the glacier. Rangers in the Saas-Grund area have monitored the Trift glacier since 2014, when they first noticed that the north face of the Weissmies mountain had broken off. But an earlier radar system that had been installed in the area was later removed due to the high price of its innovative technology. The system is said to have cost authorities around 400 francs a day, or about 417 dollars.
“In 2014, it was found that the Trift glacier in the Weissmies area moves faster than is usual for glaciers in our region. Afterwards, the behavior of the Trift glacier was closely monitored,” said Sandra Schnydrig, head of housing control at the municipality of Saas-Grund, to GlacierHub. “In the years 2015 and 2016, the glacier was permanently monitored with a radar arm and the behavior of the glacier was analyzed. At the beginning of 2017, a more simple measurement method was installed via photo analysis.”
Part of Swiss glacier breaks off after residents evacuated – Washington Post #science
There was no imminent threat until this year, when Funk saw that the glacier had begun moving again in the photos. “On Tuesday, September 5, the photo analysis showed that the Trift glacier started to move faster. Immediately afterwards, it was decided to reinstall the wheel arm measurement and to observe the behavior of the glacier more closely,” said Schnydrig. But when Funk urged authorities to reinstall the radar system, there was none available. The last radar in Switzerland had been sent to Bondo, another valley in the Swiss Alps, which recently suffered damage from an avalanche and mudslide.
Fortunately, on September 7, a radar system was sent from Germany and installed on the Trift glacier. With the proper equipment, Funk was able to predict the imminent collapse. “The degree of monitoring of this glacier is much greater than for most other glaciers in the world,” Jeff Kargel, senior associate research scientist and adjunct professor at the University of Arizona, told GlacierHub. “Technology is getting close to a point where satellite-based monitoring can detect the precursory movements of ice and result in semi-automated alerts. We are not far from being able to do that all over the world.”
The glacier will continue to be under constant evaluation. A third of the glacier’s snout remains and is unstable. Bruno Ruppen, president of the commune, was reportedly satisfied with the way the evacuation was carried out for this incident because the glacier did not cause any damage. “It could not have gone better,” he told local reporters.
The village of Saas-Grund was fortunate the recent event didn’t cause damage or casualties, but if the glacier continues to retreat at its current rate, it is assumed that more pieces of ice could break off. “The loss of ice below these remnants and the withdrawal of physical support from these pieces of the glacier means that they are very likely to fracture and slide off, especially during warm weather episodes when the ice melts, water gets in between the ice and the bed, and the whole mass becomes very slippery and weakened by fractures,” Kargel explained. “Therefore, the very common style of climate-change-driven glacier thinning, retreat, and seasonal melting is very often accompanied by this type of ice avalanche.”
A Sherpa guide has died and a foreign climber was injured following an avalanche on Mount Ama Dablam in east Nepal in late November. The avalanche was triggered by a 5.4 magnitude earthquake that occurred east of Kathmandu and nearly 11 miles west of Namche Bazar in Nepal at approximately 5:20 a.m. local time.
Lapka Thundu Sherpa, a resident of Pangboche, Solukhumbu district, and British surgeon Ciaran Hill were climbing Ama Dablam as a pair when the earthquake struck. They were reportedly only a meter apart, heading for the summit above Camp 3, over 20,669 ft., when pieces of ice dislodged during the shaking, according to Tim Mosedale, leader of the 13-member expedition.
Ama Dablam is one of the world’s most formidable and breathtaking peaks, sitting just east of Mount Everest at an elevation of 22,624 ft. Nicknamed the “Matterhorn of the Himalayas,” Ama Dablam is a prominent landmark of the Khumbu Valley for those trekking to Everest’s base camp. The mountain is well known for its hanging glacier, named the Dablam, due to its resemblance to the sacred dablam or pendant worn by Sherpa women.
Despite its aesthetic beauty, tragedy is all-too-familiar at Ama Dablam. In 2006, six climbers were killed when an avalanche impacted Camp 3 on the Southwest Ridge. In that accident, three foreigners and three Sherpa guides were killed when a serac (a pinnacle or ridge of ice on the surface of a glacier) from the Dablam glacier descended on the climbers’ tents in the early morning hours of November 13. Since then, the Dablam has become increasingly unstable, with further notable collapse in 2008.
Climbers of Ama Dablam typically summit via the Southwest Ridge, settling in at Camp 3 before the final ascent, although this route has recently been under review due to the changing nature of the glacier, which sits above and to the right of Camp 3. It is not clear whether the recent tragedy was from glacial ice breaking off, but according to Jeffrey Kargel, a geoscientist at the University of Arizona who had hiked near the mountain this past October, a treacherous-looking piece of ice was visible nearby the glacier.
“There’s some ice ready to fall,” Kargel recalls saying to his hiking companion, a trekking CEO. It was a chunk of ice right near Camp 3. Although the ice Kargel noticed might not have been the same chunk of ice involved in the deadly November ice fall, Kargel emphasized that ice falls on the Himalayan peaks are a common natural occurrence.
“My feeling is that these chunks of ice and snow are coming down all of the time. They have to come down,” said Kargel to GlacierHub. “You can see how precarious they are, perched on the side and summit of the mountain.”
This sentiment, and the feeling that the tragedy in November was natural and unavoidable, was echoed by the surviving climbers involved in the avalanche on Ama Dablam.
“I think it’s important for me to say that from my perspective it was clearly just one of those freak occurrences that could not have been predicted or avoided,” said Mr. Hill in a statement. He was ultimately saved by a long line helicopter rescue operation. “There’s no one to blame.”
Hill credited his own survival to the “flawless” response of the helicopter and ground crew. He suffered broken bones in the right hand, ribs and base of his back but is expected to recover from his injuries. Thundu Sherpa, on the other hand, suffered a fatal head injury from the falling ice, according to Mosedale, the expedition’s leader. Thundu Sherpa is survived by a wife and two children, ages 8 and 14.
“This was a tragic accident as a result of an act of nature,” added Mosedale in a statement on Facebook. “We are surrounded by an amazing panorama of massive mountains, and when the earthquake happened, there weren’t multiple avalanches and landslides. There was one incident, and our team was sadly involved.”
Typically, it is the spring melting season that presents the most dangerous time for avalanches on the mountain. Ice and snow accumulate on the peak during colder periods, but once the spring melting season hits, the wet ice begins to slip.
“In November, things would have been very hard and frozen. So you can disregard melting as a factor,” Kargel said. “Obviously it was the shaking. It is not hard to imagine that an earthquake is going to set off ice collapses. We saw that with the Gorkha Earthquake and Everest avalanches. The earthquake happened to affect ice that was poised to collapse anyway. Steep peaks and slopes have ice all of the time that is ready to come down.”
Often, glaciers of the Himalayas are relatively protected from earthquakes because the bulk of glaciers sit on valley floors, according to Kargel. The waves get absorbed and scattered before reaching the glaciers, particularly during shallow earthquakes when waves come in at acute angles relative to the surface. The peaks, on the other hand, get shaken up quite a bit during seismic events.
“If there are hanging glacier masses on the peaks, like on Aba Dablam, they can come down,” said Kargel. “Most times, this ice comes down harmlessly. It makes an avalanche, but there is nobody there.”
Otherwise, the risks are often well within the climber’s control, according to Mosedale. For instance, if it is snowing, the climbers know that avalanches will occur and the risk will be high for the 24 hours following the snow fall or longer if there is a huge dump of snow. “So we will steer clear and stay off the mountain or limit activity to safe areas,” Mosedale told GlacierHub. “But accidents can still occur that are beyond our control, as happened last November. This was an accident that couldn’t be foreseen and was completely out of the blue.”
When tragedy occurred, the team was about half way through the expedition, according to Mosedale. Thundu and Ciaran were making the first summit push. The remainder of the team were at Base Camp waiting to go to Camp 1 that day and the day after. “The client who was with Thundu was very well acclimatized, and they were going ahead of the rest of the team,” Mosedale explained to GlacierHub.
Mosedale, a 51-year old guide from Keswick, Cumbria, and a five-time Everest summitteer, made it clear that he did not want to hear negative commentary about the loss of the Sherpa guide during his expedition.
“I would prefer not to receive any comments to the effect that a climbing Sherpa has died whilst Westerners are pursuing their dreams,” said Mosedale in a statement on Facebook. “Ama Dablam is a climber’s mountain and all the people in my team are suitably well qualified by experience to be here. The climbing Sherpas are not being used and abused in the duties that they perform, they are proud of the work that they do and have worked for my Sirdar for many, many years, forming a close knit team… Five minutes either way and it would have just been a close call.”
“Sometimes the luck is just not there,” added Kargel. “This is true for scientific expeditions as well. I have had some narrow escapes from avalanches. It happens in the mountains. Sherpa guides know the chunks of ice that are unstable and make their best assessment. They know it is dangerous.”
It is clear that for some time, at least, Thundu Sherpa did attempt to avoid the dangers of the mountains, taking leave from porting to train as a watchmaker in Pittsburgh, Pennsylvania. He returned to Nepal in 2012 to co-own Kobold Watch Company Nepal (Pvt.) Ltd., alongside fellow Sherpa guide Namgel and friend Michael Kobold.
The idea for the watch subsidiary in Nepal was first proposed by Kobold, a German-born watchmaker who was indebted to the two guides for saving his wife’s life during a summit of Mount Everest, according to Elizabeth Doerr of Forbes. Kobold hoped to give the two Sherpas safer opportunities beyond the mountain. However, when the 2015 Nepal earthquake struck, hopes were dashed as the earthquake destroyed the watch company. Following the collapse of the enterprise, Thundu Sherpa headed back to work on the mountains.
“Of slight build, endowed with a quiet voice and an unfailingly humble demeanor, Thundu was nonetheless considered a giant among his peers — the exclusive club of Nepali mountain guides,” wrote Michael Kobold in a tribute to his friend Thundu in the Nepali Times. Thundu began his journey to high altitude porter as a kitchen boy and later became a cook on expeditions, according to Kobold.
“Thundu had a very gentle persona but was incredibly strong and talented in the mountains,” added Mosedale, in conversation with Glacierhub. “He had a great attention to detail, and because he had worked so often with Westerners, he had a very good understanding of what they usually required. Some Sherpas are very strong but don’t get the social differences, whereas Thundu had that extra level of understanding which made him stand out.”
On Everest, there has been much talk of changing the primary course that climbers take up the mountain following multiple tragic mountaineering disasters and deaths of Sherpas in recent years. A similar discussion may need to take place on Ama Dablam, which has become increasingly popular, dangerous and overcrowded by climbers in the autumn months, according to notable American mountaineer Alan Arnette of alanarnette.com. Arnette is a 2011 Everest summiter and the oldest American to summit K2. When asked whether he would personally summit Ama Dablam again following an expedition in 2000, Arnette cited the risks given the recent instability of the Dablam. “No. It is too dangerous given the avalanches off the Dablam. While climbers summited in 2008, many did not given the new difficulties,” he said. “A modification was put in during the fall of 2008 which takes the route further to the right of the Dablam. This somewhat avoids the avalanche danger but now is over steep blue ice making the summit bid more difficult. As of 2012, teams continue to climb without serious incident but many choose to bypass Camp 3 and have a very, very long day from Camp 2 to the summit.”
A key to reducing chances of tragedy seems to be making sure that climbers don’t sleep or rest below unstable ice masses when an earthquake hits, but the difficulty obviously lies in predicting the earthquake. “The truth is, you really can’t predict an earthquake,” said Kargel. “As climbers, they know that avalanches happen frequently. Maybe infrequently enough that people are still willing to take the risk. The danger doesn’t mean that climbers should stop climbing or that Sherpa guides should stop their work. But obviously these mountains are very dangerous and these deaths are going to occur regularly. It is an unfortunate aspect of this pursuit by human beings to conquer peaks.”
Glaciers can play an important role in landscape dynamics, interacting with other factors to shape landscape development. Two days after a 7.8 magnitude earthquake struck North Canterbury, New Zealand, a landslide occurred between nearby Fox and Franz Josef glaciers. This landslide could offer insight into the role of glaciers in seismically active areas, particularly concerning the ways in which glaciers interact with earthquake-related instabilities in the landscape.
The landslide occurred at Omoeroa at around 2 p.m. (GMT +12 hours) on November 16th, closing off a section of State Highway 6 along the west coast of South Island for about three hours until debris were cleared.
Earthquakes and landslides are common in New Zealand due to the country’s location on the Pacific Ring of Fire, the area around the Pacific Ocean that is very seismically active. It is so named because of the prevalence of volcanic activity within the ring, which is made up by the major tectonic plate boundaries.
Earthquakes, which occur when Earth’s crust breaks along faults (fractures in the crust), send tremors outwards from the point of breakage. This particular earthquake was caused by oblique-reverse faulting (faulting that had both strike-slip and reverse components) near the boundary of the Pacific and Australian tectonic plates. Landslides, like the one that occurred between the two glaciers, are often triggered by other natural disasters, such as earthquakes or floods. In this case, the earthquake and its aftershocks triggered up to 100,000 landslides, causing local damage and blocking major roads and railway routes.
In conversation with GlacierHub, Umesh Haritashya, an associate professor in environmental geology at the University of Dayton, explained that the region in which the landslide occurred is prone to landslides even without any seismic activity. This is due to the topography of New Zealand’s Southern Alps. As such, it would not be surprising if the earthquake, landslide and glaciers are connected, he said.
While the two glaciers are found on the west coast of South Island, the earthquake occurred on the east coast of the island. The distance between the two suggests that the intensity of the tremors experienced in the area around the landslide may have been quite low. Nonetheless, a link is possible, according to Jeff Kargel, a geoscientist at the University of Arizona. “The timing of this big landslide is certainly suggestive of a direct link to the earthquake,” Kargel told GlacierHub.
“For both direct and circumstantial reasons, earthquakes, glaciers and landslides are closely associated,” Kargel explained. “There is the direct influence of glaciers that produce lots of unstable rock debris over thousands of years, and there are indirect influences, where glaciers erode the mountain topography and produce very steep slopes. These factors create conditions under which seismic activity can easily set off landslides.”
In addition, Kargel noted that glaciers occur where uplift rates have been high and the terrain is elevated to begin with. This means that either circumstantially or indirectly, glaciers and landslides can occur nearby.
Kargel further stated that large earthquakes tend to create instabilities in the landscape that are later exploited by natural processes, making landslides more frequent in the aftermath of earthquakes. “The spike in landslide activity can last for several years,” he said.
In addition to seismic activity, other causes like heavy rain after the earthquake could have contributed to the occurrence of the landslide. New Zealand’s MetService reported that the areas of the glaciers had received considerable rain, with 80-120mm falling the night after the earthquake.
“The West Coast receives an unusually high amount of rain, so slopes are already reconditioned and any seismic activity can trigger major landslides,” Haritashya explained.
The links between the earthquake, glaciers and landslides will become clearer as scientists examine similar events more fully. For now, landslides like these offer an insight into the complex interactions between glaciers, topography and seismic activity. Earthquakes can cause large amounts of disruption to people’s lives, so advancements in this field of science could prove valuable to communities as they seek to address the challenges posed by natural disasters.