How Climate Change Could Trigger Large Landslides And Mega-Tsunamis

How Climate Change Could Trigger Large Landslides And Mega-TsunamisPeople inspect the damage following a tsunami at a village in Sumur, Indonesia, on Dec. 24, 2018. (AP Photo/Fauzy Chaniago)

Just over 60 years ago, a giant wave washed over the narrow inlet of Lituya Bay, Alaska, knocking down the forest, sinking two fishing boats and claiming two lives.

A nearby earthquake had triggered a rockslide into the bay, suddenly displacing massive volumes of water. The large landslide tsunami reached a height of more than 160 metres and caused a run-up (the vertical height that a wave reaches up a slope) of 524 metres above sea level. For perspective, imagine run-up to about the height of the CN Tower in Toronto (553 metres) or One World Trade Center in New York City (541 metres).

Large landslides, like the one that hit Lituya Bay in 1958, are mixtures of rock, soil and water that can move very quickly. When a landslide hits a body of water, it can generate waves, especially in mountainous coastal areas, where steep slopes meet a fiord, lake or reservoir. Although mega-tsunamis are often sensationalized in the news, real and scientifically documented events motivate new research.

In late July, a 7.8 magnitude earthquake near Perryville, Alaska, triggered a tsunami warning for south Alaska, the Aleutian Islands and the Alaskan Peninsula. And scientists recently warned that a retreating glacier in a fiord in Prince William Sound, Alaska, had elevated the risk of a landslide and tsunami in a popular fishing and tourism area not far from the town of Whittier.

International research efforts are urgently underway to better understand these major natural hazards. This is critically important, since climate change could contribute to increasing the number and size of these events.

Recent giant wave events

Triggered by either an earthquake or higher than normal rainfall, another massive landslide occurred in Alaska in 2015. This one was in Taan Fiord, 500 kilometres east of Anchorage. This event was so powerful, it released an enormous amount of energy and registered as a magnitude 4.9 earthquake, approximately equal to the explosive force of 340 tons of TNT.

The landslide impact into the water was so strong that it generated seismic signals that were detected at monitoring stations in the United States and around the world. The impact generated a wave with a run-up of 193 metres. Thankfully, the area is remote and no one was killed.

However, the 2017 landslide into Karrat Fiord, Greenland, was deadly. It generated a 90 metre high tsunami at the impact site. This wave propagated 30 kilometres to the community of Nuugaatsiaq, wiping it out and killing four people. Other major landslide wave events have recently occurred in Norway and British Columbia.

Tsunamis are also generated by other mechanisms including earthquakes, volcanic collapse and submarine landslides. Earthquakes can trigger massive submarine landslides, which have been shown to be major contributors to the maximum tsunami run-up. This occurred when earthquakes struck Japan in 2011 and New Zealand in 2016, resulting in run-up of 40 metres and seven metres in each case.

Predicting the wave size

Large landslide tsunamis are difficult or impossible to measure in the field. They typically occur in mountainous regions with very steep slopes, and therefore are usually far from big cities. Geologists have documented many of the cases by mapping the run-up elevations or deposits of trees and rocks washed off slopes after these events, like in Taan Fiord.

But these natural hazards pose a major threat to society. What if a landslide into a reservoir creates a wave that overtops a dam? This happened in 1963 in Vajont, Italy, killing more than 2,000 people who lived downstream.

A better understanding of how landslides generate waves is crucial. Experimental studies are a way to gain insight into these waves. Laboratory tests have led to empirical equations to predict the size of landslide tsunamis.

Recent research with detailed measurements using high-speed digital cameras is helping to determine the controls of the landslide properties on the generation of waves. This has led to new research at Queen’s University that has improved the theoretical understanding of how landslides transfer momentum to water and generate waves.

The wave size depends on the thickness and speed of the slide at impact. The shape of these waves can now be predicted and along with the wave amplitude (the distance from rest to crest), and be used as input to computer models for wave propagation and full simulation of landslide wave generation. These models can help understand and predict the behaviour of waves at the laboratory scale and at the field scale in coastal environments.

Past and future events

Since 1900, there have been eight confirmed massive wave events where large landslides have generated waves greater than 30 metres high. Two of these led to over 100 deaths in Norway in the 1930s. Of these eight major events, four have occurred since 2000.

How Climate Change Could Trigger Large Landslides And Mega-Tsunamis Rescuers help a young girl and her family during an evacuation of homes on Sebuku Island, Indonesia. On Dec. 22, 2018, the flank of the Anak Krakatau volcano failed, generating a tsunami that killed more than 400 people. (AP Photo/Fauzy Chaniago)

However, other events with smaller waves have devastated more populated coasts. For example, the collapse of the Anak Krakatau volcano in 2018 generated a tsunami on the coast of Indonesia that caused over 400 casualties and major infrastructure damage.

Will more of these events occur in the future? Climate change could influence the frequency and magnitude of these natural hazards.

A warming climate certainly changes northern and alpine environments in many ways. This can include permafrost thawing, retreating glaciers and iceberg calving, more frequent freeze-thaw cycles and increased rainfall or other hydraulic triggers. All of these can contribute to destabilizing rock slopes and increase the risk of a major landslide into water.

These natural hazards can’t be prevented, but damage to infrastructure and populations can be minimized. This can be achieved through scientific understanding of the physical processes, site-specific engineering risk analysis and coastal management of hazard-prone regions.The Conversation

About The Author

Ryan P. Mulligan, Associate Professor of Civil Engineering, Queen's University, Ontario and Andy Take, Professor, Department of Civil Engineering, Queen's University, Ontario

Related Books

Life After Carbon: The Next Global Transformation of Cities

by Peter Plastrik , John Cleveland
1610918495The future of our cities is not what it used to be. The modern-city model that took hold globally in the twentieth century has outlived its usefulness. It cannot solve the problems it helped to create—especially global warming. Fortunately, a new model for urban development is emerging in cities to aggressively tackle the realities of climate change. It transforms the way cities design and use physical space, generate economic wealth, consume and dispose of resources, exploit and sustain the natural ecosystems, and prepare for the future. Available On Amazon

The Sixth Extinction: An Unnatural History

by Elizabeth Kolbert
1250062187Over the last half-billion years, there have been Five mass extinctions, when the diversity of life on earth suddenly and dramatically contracted. Scientists around the world are currently monitoring the sixth extinction, predicted to be the most devastating extinction event since the asteroid impact that wiped out the dinosaurs. This time around, the cataclysm is us. In prose that is at once frank, entertaining, and deeply informed, New Yorker writer Elizabeth Kolbert tells us why and how human beings have altered life on the planet in a way no species has before. Interweaving research in half a dozen disciplines, descriptions of the fascinating species that have already been lost, and the history of extinction as a concept, Kolbert provides a moving and comprehensive account of the disappearances occurring before our very eyes. She shows that the sixth extinction is likely to be mankind's most lasting legacy, compelling us to rethink the fundamental question of what it means to be human. Available On Amazon

Climate Wars: The Fight for Survival as the World Overheats

by Gwynne Dyer
1851687181Waves of climate refugees. Dozens of failed states. All-out war. From one of the world’s great geopolitical analysts comes a terrifying glimpse of the strategic realities of the near future, when climate change drives the world’s powers towards the cut-throat politics of survival. Prescient and unflinching, Climate Wars will be one of the most important books of the coming years. Read it and find out what we’re heading for. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you,, and at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.


This article is republished from The Conversation under a Creative Commons license. Read the original article.


follow InnerSelf on

facebook icontwitter iconyoutube iconinstagram iconpintrest iconrss icon

 Get The Latest By Email

Weekly Magazine Daily Inspiration


The Great Climate Migration Has Begun
The Great Climate Migration Has Begun
by Super User
The climate crisis is forcing thousands around the world to flee as their homes become increasingly uninhabitable.
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
The Last Ice Age Tells Us Why We Need To Care About A 2℃ Change In Temperature
by Alan N Williams, et al
The latest report from the Intergovernmental Panel on Climate Change (IPCC) states that without a substantial decrease…
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
Earth Has Stayed Habitable For Billions Of Years – Exactly How Lucky Did We Get?
by Toby Tyrrell
It took evolution 3 or 4 billion years to produce Homo sapiens. If the climate had completely failed just once in that…
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
How Mapping The Weather 12,000 Years Ago Can Help Predict Future Climate Change
by Brice Rea
The end of the last ice age, around 12,000 years ago, was characterised by a final cold phase called the Younger Dryas.…
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
The Caspian Sea Is Set To Fall By 9 Metres Or More This Century
by Frank Wesselingh and Matteo Lattuada
Imagine you are on the coast, looking out to sea. In front of you lies 100 metres of barren sand that looks like a…
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
Venus Was Once More Earth-like, But Climate Change Made It Uninhabitable
by Richard Ernst
We can learn a lot about climate change from Venus, our sister planet. Venus currently has a surface temperature of…
Five Climate Disbeliefs: A Crash Course In Climate Misinformation
The Five Climate Disbeliefs: A Crash Course In Climate Misinformation
by John Cook
This video is a crash course in climate misinformation, summarizing the key arguments used to cast doubt on the reality…
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
The Arctic Hasn't Been This Warm For 3 Million Years and That Means Big Changes For The Planet
by Julie Brigham-Grette and Steve Petsch
Every year, sea ice cover in the Arctic Ocean shrinks to a low point in mid-September. This year it measures just 1.44…


green energy2 3
Four Green Hydrogen Opportunities for the Midwest
by Christian Tae
To avert a climate crisis, the Midwest, like the rest of the country, will need to fully decarbonize its economy by…
Major Barrier to Demand Response Needs to End
by John Moore, On Earth
If federal regulators do the right thing, electricity customers across the Midwest may soon be able to earn money while…
trees to plant for climate2
Plant These Trees To Improve City Life
by Mike Williams-Rice
A new study establishes live oaks and American sycamores as champions among 17 “super trees” that will help make cities…
north sea sea bed
Why We Must Understand Seabed Geology To Harness The Winds
by Natasha Barlow, Associate Professor of Quaternary Environmental Change, University of Leeds
For any country blessed with easy access to the shallow and windy North Sea, offshore wind will be key to meeting net…
3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
3 wildfire lessons for forest towns as Dixie Fire destroys historic Greenville, California
by Bart Johnson, Professor of Landscape Architecture, University of Oregon
A wildfire burning in hot, dry mountain forest swept through the Gold Rush town of Greenville, California, on Aug. 4,…
China Can Meet Energy and Climate Goals Capping Coal Power
China Can Meet Energy and Climate Goals Capping Coal Power
by Alvin Lin
At the Leader’s Climate Summit in April, Xi Jinping pledged that China will “strictly control coal-fired power…
Blue water surrounded by dead white grass
Map tracks 30 years of extreme snowmelt across US
by Mikayla Mace-Arizona
A new map of extreme snowmelt events over the last 30 years clarifies the processes that drive rapid melting.
A plane drops red fire retardant on to a forest fire as firefighters parked along a road look up into the orange sky
Model predicts 10-year burst of wildfire, then gradual decline
by Hannah Hickey-U. Washington
A look at the long-term future of wildfires predicts an initial roughly decade-long burst of wildfire activity,…

 Get The Latest By Email

Weekly Magazine Daily Inspiration

New Attitudes - New Possibilities | | | InnerSelf Market
Copyright ©1985 - 2021 InnerSelf Publications. All Rights Reserved.