TONOSÍ, October 18, 2026 — A magnitude 7.5 earthquake that struck Panama on October 9 triggered at least 2,351 landslides, according to a preliminary analysis of satellite images by the Institute of Geosciences of the University of Panama. The ground movements were identified through image processing from the Copernicus Sentinel-2 L2A system, which mapped the affected areas following the earthquake recorded at 12:56 pm, with its epicenter 39 kilometers northwest of Tonosí in Los Santos province.
The Mechanics of Slope Failure
Landslides, also known as landslips, rockslips, rockfalls, mudslides, mudslips, or rockslides, are several forms of mass wasting that include rockfalls, mudflows, shallow or deep-seated slope failures, and debris flows, according to Wikipedia data. These events occur in environments characterized by either steep or gentle slope gradients, ranging from mountain ranges to coastal cliffs and underwater areas known as submarine landslides. Gravity serves as the primary driving force for a landslide to occur, pulling earth downward when a slope shifts from stable to unstable.
According to Wikipedia, this instability stems from a decrease in the shear strength of the slope material, an increase in the shear stress borne by the material, or a combination of both. Natural triggers include an increase in water content or saturation by rain infiltration, snowmelt, or melting glaciers. Rising groundwater and increased pore water pressure from rainy season aquifer recharge, along with higher hydrostatic pressure in cracks and fractures, also contribute to slope failure. Additional natural factors involve the loss of vertical vegetative structure and soil nutrients after a wildfire, river or sea wave erosion at the top of a slope, and physical and chemical weathering such as freeze-thaw cycles or mineral dissolution.
How Seismic Activity and Climate Stressors Trigger Mass Wasting
Ground shaking caused by earthquakes acts as a direct destabilizing force by inducing soil liquefaction, or by weakening the material to produce movements that eventually result in a landslide, according to Wikipedia. Volcanic eruptions, changes in pore fluid composition, and seasonal or climate change-induced temperature shifts also alter slope stability. Furthermore, Wikipedia notes that global warming and other human impacts increase the frequency of extreme weather events that trigger landslides.
Human activities heavily aggravate these risks through deforestation, cultivation, construction, and resource exploitation like mining, according to Wikipedia. Vibrations from machinery or traffic, blasting, and earthwork alter the shape of slope structures or impose new loads on the ground. In shallow soils, the removal of deep-rooted vegetation that binds colluvium to bedrock increases vulnerability, while urbanization and agricultural logging change how water infiltrates the soil.
The Growing Threat of Landslide-Generated Tsunamis in Alaska
Similar physical dynamics create severe maritime hazards in remote regions, as seen along the southern coast of Alaska where steep slopes sit above deep fjords, according to reporting by Alaska Public Media. Geologist Chad Hults, formerly with the National Park Service, stated that this combination creates the recipe for deep-seated landslides capable of generating waves hundreds of feet high. Melenda Lekanof, a resident of Yakutat, noted the direct peril to maritime traffic when observing a ridge marked with deep vertical gashes near tour routes. Public awareness surged after the second-tallest tsunami on record hit Tracy Arm in August 2025, a fjord south of Juneau frequented by cruise ships, according to Alaska Public Media.
Alix Pierce, Juneau’s visitor industry director, explained that cruise vessels frequently seek out tidewater glaciers, pushing ships toward unregulated areas like Disenchantment Bay or South Sawyer Glacier where landslide tsunami risk is growing. Casey Mapes, who served as a volunteer fire department chief in Yakutat for 12 years, warned that communities lack the personnel to mount immediate rescue responses if a wave strikes a vessel carrying tourists or commercial fishermen.
Challenges in Monitoring and Mitigation
Monitoring dangerous slopes remains an enormous undertaking due to Alaska’s sprawling, remote geography and limited funding, according to Alaska Public Media. Scientists currently lack a foolproof method to determine if a specific slope is about to fail or to provide advance warnings. In Panama, the Institute of Geosciences warned that its count of 2,351 landslides is preliminary because cloud cover during the satellite’s passage blocked observation in some areas, meaning the total may increase as new images are validated.
Government figures in Panama reported that the October 9 earthquake left one dead, 26 injured, and nearly 3,000 homes damaged alongside 22 damaged bridges, while 92% of structurally collapsed roads had been reopened by October 16. Authorities assisted 22,400 people, assessed 6,800 families, and maintained 46 shelters for displaced residents across the most heavily impacted provinces of Coclé, Herrera, Los Santos, and Veraguas.
Satellite Monitoring Limitations in Cloudy Conditions
The Institute of Geosciences warned that its count of 2,351 landslides is preliminary because cloud cover during the satellite’s passage blocked observation in some areas, meaning the total may increase as new images are validated.
The analysis provides a first approximation of the magnitude of the earth movements triggered by the earthquake, although it has not yet been specified how many of these landslides affected roads, homes or other infrastructure.
For this reason, the figure of 2,351 landslides could increase as new images are incorporated and the validation of information on the ground progresses.
Human Impact and Environmental Stressors
Human activities, including urban sprawl, resource exploitation, mining, and deforestation, frequently exacerbate the risk of landslides. These actions often lead to land degradation, which reduces the ability of vegetation to stabilize soil. Furthermore, construction, blasting, and vibrations from traffic or heavy machinery can alter the structural shape of slopes or impose new, destabilizing loads on the ground. In shallow soil environments, the removal of deep-rooted vegetation that binds colluvium to bedrock significantly increases vulnerability, while urbanization and agricultural logging practices change how water infiltrates the soil.
Beyond direct human development, broader environmental changes play a critical role in slope stability. According to Wikipedia, global warming and other human impacts on the environment increase the frequency of extreme weather events that trigger landslides. Climate change also induces temperature shifts that alter slope conditions, contributing to the growing intensity of natural hazards. These stressors, combined with human-driven land-use changes, create conditions where slopes are more prone to failure, often leading to disasters that require complex mitigation policies and practices to reduce the associated risks to human life and infrastructure.
Sources
- 2351+ Landslides at Least were Caused by the Earthquake in Panama. – Newsroom Panama
- Landslide
- The risk from landslide tsunamis is intensifying in busy Alaska fjords, with no plan in place
Photo: Archives New Zealand from New Zealand (CC BY-SA 2.0)
