A volcanic landslide or volcanogenic landslide is a type of mass wasting that takes place at volcanoes.
A volcanic landslide or volcanogenic landslide is a type of mass wasting that takes place at volcanoes.
All volcanic edifices are susceptible to landslides, particularly stratovolcanoes and shield volcanoes where landslides are important processes. [1] Volcanic landslides range in size from less than 1 km3 (0.24 cu mi) to more than 100 km3 (24 cu mi). [2] The largest volcanic landslides on Earth occur from submarine volcanoes and are several times larger than those that occur on land. Submarine landslides with volumes of 100–150 km3 (24–36 cu mi) have occurred in the Canary Islands within the last 43 million years, but the largest submarine landslides could have been up to 900 km3 (220 cu mi) in volume. [3] Massive submarine landslides have also taken place in the Hawaiian Islands over the last several million years, the largest of which constitute significant portions of the islands from which they originated. [4]
Smaller landslides have also been identified at volcanoes on Mars and Venus. [5] [6] Martian landslides reach lengths of 90 km (56 mi) and more while the largest Venusian landslides extend only about 50 km (31 mi). The most dramatic landslide deposits on Venus occur beneath the slopes of volcanoes. Since erosion rates on Venus are much lower than those on Earth due to the lack of water on the surface, landslides are an important mechanism in wearing down mountain regions on Venus. The rounded hills of the complexly deformed tessera, or tile-like, terrain on Venus have probably been modified by numerous landslides. [6]
At volcanoes, the term landslide is commonly used for slope movements with shear and displacement in a relatively narrow zone. [7] They can be in the form of debris avalanches, debris flows, slumps and rockfalls. [7] [8] A debris avalanche is a sudden, very rapid flow of rock and soil in response to gravity. It is a common middle stage in the transformation of a cohesive debris flow from a landslide or rockslide. Debris avalanches may be restricted to grain flows or granular flows, in which flow mechanics are governed by particle interactions involving friction and collision. Debris flows, in contrast, owe much of their behaviour to excess pore-water pressure and a pore fluid that is viscous and contains fine sediment. [7]
The largest landslides from volcanoes are called sector or edifice collapses. [7] Prehistoric sector collapses are preserved in the geological record in the form of debris avalanche deposits and collapse scars. [9] [10] [11] Debris avalanche deposits can be found up to 20 km (12 mi) from the site of collapse. Collapse scars are also an indicator of sector collapse and are often described as "amphitheatre" or "horseshoe" shaped. [11] Such collapse scars, open at one end, have long been noted in many volcanic regions around the world. [2] The largest volcanic island sector collapse in historic times took place in 1888 when Ritter Island collapsed off the northern coast of Papua New Guinea. [12] [13] Edifice reconstruction generally must occur before a second sector collapse. [7]
Flank collapses are much smaller than sector collapses but they may also yield far-reaching debris flows. Flank collapses differ from sector collapses in that they only involve the volcano flank while sector collapses are large enough to involve the volcano summit. The smaller size of a flank collapse indicates that there need be no repose time before another flank collapse occurs, and hence they can be treated as random events. [7]
Several conditions can trigger landslides at volcanoes:
Large landslides from volcanoes often bury valleys with tens to hundreds of metres of rock debris, forming a chaotic landscape marked by dozens of small hills and closed depressions. If the deposit is thick enough, it may dam streams to form lakes. These lakes may eventually drain catastrophically to create floods and lahars downstream. [2]
Landslides that remove a large portion of a volcanic cone may abruptly decrease pressure on shallow magmatic and hydrothermal systems, which can generate explosions ranging from a small steam explosion to large steam and magma-driven directed blasts. These result in tephra and ash fall hazards for surrounding areas. [2]
Large horseshoe-shaped craters formed by landslides at volcanoes will likely direct subsequent lava flows, pyroclastic flows or lahars toward its breached opening if the primary eruptive vent is located within these deep craters. [2]
The collapse of island or coastal volcanoes from giant landslides can generate tsunamis that could potentially devastate large areas of coastal land. [23]
Historically, the most deadly volcanic landslide occurred in 1792 when sliding debris from Mount Mayuyama in Japan slammed into the Ariake Sea and generated a tsunami that reached the opposite shore and killed nearly 15,000 people. [2]
The sector collapse of Ritter Island in 1888 generated a tsunami with runups of up to 15 m (49 ft) that caused damage more than 700 km (430 mi) away and killed anywhere between 500 and 3,000 people on neighbouring islands. [24] [25] [26]
A landslide originating from Devastation Glacier on the southern flank of the Mount Meager massif in British Columbia, Canada, buried and killed a group of four geologists at the confluence of Devastation Creek and Meager Creek in July 1975. [27] [28]
In 1979, a landslide from the Indonesian volcano Illiwerung produced 9 m-high (30 ft) waves that killed more than 500 people. [29] In December 2018, another landslide-induced tsunami took place in Indonesia's Sunda Strait following a collapse of Anak Krakatoa. [30] The waves struck about 313 km (194 mi) of coastline with various heights, killing at least 373 people and damaging many buildings. [31] [32]
Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients, from mountain ranges to coastal cliffs or even underwater, in which case they are called submarine landslides.
A megatsunami is a very large wave created by a large, sudden displacement of material into a body of water.
A geologic hazard or geohazard is an adverse of geologic condition capable of causing widespread damage or loss of property and life. These hazards are geological and environmental conditions and involve long-term or short-term geological processes. Geohazards can be relatively small features, but they can also attain huge dimensions and affect local and regional socio-economics to a large extent.
The Cumbre Vieja is an active volcanic ridge on the island of La Palma in the Canary Islands, Spain. The spine of Cumbre Vieja trends in an approximate north–south direction, comprising the southern half of La Palma, with both summit ridge and flanks pockmarked by dozens of craters and cones. The latest eruption began on 19 September 2021 in a forested area of Las Manchas locality known as Cabeza de Vaca. Voluminous lava flows quickly reached populated areas downslope, fanning out across settlements and banana plantations, destroying thousands of buildings and ultimately pouring over steep cliffs into the ocean to enlarge the island at several locations. The volcano went quiet on 13 December 2021, and on 25 December 2021, the local government declared the eruption to be over.
Mass wasting, also known as mass movement, is a general term for the movement of rock or soil down slopes under the force of gravity. It differs from other processes of erosion in that the debris transported by mass wasting is not entrained in a moving medium, such as water, wind, or ice. Types of mass wasting include creep, solifluction, rockfalls, debris flows, and landslides, each with its own characteristic features, and taking place over timescales from seconds to hundreds of years. Mass wasting occurs on both terrestrial and submarine slopes, and has been observed on Earth, Mars, Venus, Jupiter's moon Io, and on many other bodies in the Solar System.
The Almolonga volcano, also called "Cerro Quemado" or "La Muela" due to its distinct shape, is an andesitic stratovolcano in the south-western department of Quetzaltenango in Guatemala. The volcano is located near the town of Almolonga, just south of Quetzaltenango, Guatemala's second largest city.
Socompa is a large stratovolcano at the border of Argentina and Chile with an elevation of 6,051 metres (19,852 ft) metres. Part of the Chilean and Argentine Andean Volcanic Belt (AVB), it is part of the Central Volcanic Zone, one of the various segments of the AVB. This part of the Andean volcanic arc begins in Peru and runs first through Bolivia and Chile, and then through Argentina and Chile, and contains about 44 active volcanoes. Socompa lies close to the pass of the same name, where the Salta-Antofagasta railway crosses the border.
The Hilina Slump, on the south flank of the Kīlauea Volcano on the southeast coast of the Big Island of Hawaiʻi, is the most notable of several landslides that ring each of the Hawaiian Islands. These landslides are the means by which material deposited at a volcano's vents are transferred downward and seaward, eventually spilling onto the seabed to broaden the island.
A mudflow, also known as mudslide or mud flow, is a form of mass wasting involving fast-moving flow of debris and dirt that has become liquified by the addition of water. Such flows can move at speeds ranging from 3 meters/minute to 5 meters/second. Mudflows contain a significant proportion of clay, which makes them more fluid than debris flows, allowing them to travel farther and across lower slope angles. Both types of flow are generally mixtures of particles with a wide range of sizes, which typically become sorted by size upon deposition.
Submarine landslides are marine landslides that transport sediment across the continental shelf and into the deep ocean. A submarine landslide is initiated when the downwards driving stress exceeds the resisting stress of the seafloor slope material, causing movements along one or more concave to planar rupture surfaces. Submarine landslides take place in a variety of different settings, including planes as low as 1°, and can cause significant damage to both life and property. Recent advances have been made in understanding the nature and processes of submarine landslides through the use of sidescan sonar and other seafloor mapping technology.
The Canadian Cascade Arc, also called the Canadian Cascades, is the Canadian segment of the North American Cascade Volcanic Arc. Located entirely within the Canadian province of British Columbia, it extends from the Cascade Mountains in the south to the Coast Mountains in the north. Specifically, the southern end of the Canadian Cascades begin at the Canada–United States border. However, the specific boundaries of the northern end are not precisely known and the geology in this part of the volcanic arc is poorly understood. It is widely accepted by geologists that the Canadian Cascade Arc extends through the Pacific Ranges of the Coast Mountains. However, others have expressed concern that the volcanic arc possibly extends further north into the Kitimat Ranges, another subdivision of the Coast Mountains, and even as far north as Haida Gwaii.
Tanganasoga is the main volcano of El Hierro's El Golfo area in the Canary Islands, consisting of a cinder cone. The volcano is part of a much larger shield volcano system.
The 2010 Mount Meager landslide was a large catastrophic debris avalanche that occurred in southwestern British Columbia, Canada, on August 6 at 3:27 a.m. PDT (UTC-7). More than 45,000,000 m3 (1.6×109 cu ft) of debris slid down Mount Meager, temporarily blocking Meager Creek and destroying local bridges, roads and equipment. It was one of the largest landslides in Canadian history and one of over 20 landslides to have occurred from the Mount Meager massif in the last 10,000 years.
Mount Cayley is an eroded but potentially active stratovolcano in the Pacific Ranges of southwestern British Columbia, Canada. Located 45 km (28 mi) north of Squamish and 24 km (15 mi) west of Whistler, the volcano resides on the edge of the Powder Mountain Icefield. It consists of massif that towers over the Cheakamus and Squamish river valleys. All major summits have elevations greater than 2,000 m (6,600 ft), Mount Cayley being the highest at 2,385 m (7,825 ft). The surrounding area has been inhabited by indigenous peoples for more than 7,000 years while geothermal exploration has taken place there for the last four decades.
A sector collapse or lateral collapse is the structural failure and subsequent collapse of part of a volcano. Unlike a flank collapse, a sector collapse involves the central volcanic pipe. Sector collapses are one of the most hazardous volcanic events, often resulting in lateral blasts, landslides, and changes in volcanic eruptive behavior. Sector collapse can be caused by earthquakes, volcanic eruptions, gradual volcanic deformation, and other processes. Sector collapse events can occur on volcanoes present at both convergent and divergent plate boundaries. Sector collapses are generally very sudden; however, some attempts have been made to predict collapse events.
The island of La Palma in the Canary Islands is at risk of undergoing a large landslide, which could cause a tsunami in the Atlantic Ocean. Volcanic islands and volcanoes on land frequently undergo large landslides/collapses, which have been documented in Hawaii for example. A recent example is Anak Krakatau, which collapsed to cause the 2018 Sunda Strait tsunami.
On the morning of March 13, 1888, an explosion took place on Ritter Island, a small volcanic island in the Bismarck and Solomon Seas, between New Britain and Umboi Island. The explosion resulted in the collapse of most of the island and generated a tsunami with runups of up to 15 meters (49 ft) that caused damage more than 700 kilometers (430 mi) away and killed anywhere between 500 and 3,000 on neighbouring islands, including scientists and explorers. This event is the largest volcanic island sector collapse in recent history.
The devastating eruption of Oshima–Ōshima began on 18 August 1741 and ended on 1 May the next year. Eleven days into the eruption, the Kampo tsunami with estimated maximum heights of over 90 meters swept across neighboring islands in Japan and the Korean Peninsula.
A volcanic tsunami, also called a volcanogenic tsunami, is a tsunami produced by volcanic phenomena. About 20–25% of all fatalities at volcanoes during the past 250 years have been caused by volcanic tsunamis. The most devastating volcanic tsunami in recorded history was that produced by the 1883 eruption of Krakatoa. The waves reached heights of 40 m (130 ft) and killed 36,000 people.
This article incorporates public domain material from websites or documents of the United States Geological Survey .
This article incorporates public domain material from websites or documents of the National Aeronautics and Space Administration .Cleggett-Halaim, Paula; Doyle, Jim (1992). "Large Landslides Found on Venus". NASA . Retrieved 14 April 2023.