A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of
mudflow
A mudflow or mud flow is a form of mass wasting involving fast-moving flow of debris 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 significa ...
or
debris flow
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally ...
composed of a
slurry
A slurry is a mixture of denser solids suspended in liquid, usually water. The most common use of slurry is as a means of transporting solids or separating minerals, the liquid being a carrier that is pumped on a device such as a centrifugal pu ...
of
pyroclastic
Pyroclastic rocks (derived from the el, πῦρ, links=no, meaning fire; and , meaning broken) are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroc ...
material, rocky debris and water. The material flows down from a
volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates are ...
, typically along a
river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...
valley
A valley is an elongated low area often running between Hill, hills or Mountain, mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers ...
.
Lahars are extremely destructive: they can flow tens of metres per second, they have been known to be up to deep, and large flows tend to destroy any structures in their path. Notable lahars include those at
Mount Pinatubo
Mount Pinatubo is an active stratovolcano in the Zambales Mountains, located on the tripoint boundary of the Philippine provinces of Zambales, Tarlac and Pampanga, all in Central Luzon on the northern island of Luzon. Its eruptive history w ...
and
Nevado del Ruiz
The Nevado del Ruiz (), also known as La Mesa de Herveo ( en, Mesa of Herveo, the name of the nearby town) is a volcano on the border of the departments of Caldas and Tolima in Colombia, about west of the capital city Bogotá. It is a strat ...
, the latter of which
killed thousands of people in the town of
Armero
Armero is a municipality in the Tolima Department, Colombia. According to the National Department of Statistics of Colombia, 12,852 lived in the town in 2005. Its median temperature is 27 °C. It was founded in 1895, but was not officia ...
.
Etymology
The word ''lahar'' is of
Javanese origin.
Berend George Escher
Berend George Escher (4 April 1885 – 11 October 1967) was a Dutch geologist.
Escher had a broad interest, but his research was mainly on crystallography, mineralogy and volcanology. He was a pioneer in experimental geology. He was a half- ...
introduced it as a geological term in 1922.
Description
![Sambisari 01](https://upload.wikimedia.org/wikipedia/commons/e/e3/Sambisari_01.jpg)
The word ''lahar'' is a general term for a flowing mixture of water and pyroclastic debris. It does not refer to a particular
rheology
Rheology (; ) is the study of the flow of matter, primarily in a fluid ( liquid or gas) state, but also as "soft solids" or solids under conditions in which they respond with plastic flow rather than deforming elastically in response to an appl ...
or
sediment
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...
concentration.
Lahars can occur as normal stream flows (sediment concentration of less than 30%), hyper-concentrated stream flows (sediment concentration between 30 and 60%), or debris flows (sediment concentration exceeding 60%). Indeed, the rheology and subsequent behaviour of a lahar may vary in place and time within a single event, owing to changes in sediment supply and water supply.
Lahars are described as 'primary' or 'syn-eruptive' if they occur simultaneously with or are triggered by primary volcanic activity. 'Secondary' or 'post-eruptive' lahars occur in the absence of primary volcanic activity, e.g. as a result of rainfall during pauses in activity or during dormancy.
In addition to their variable rheology, lahars vary considerably in magnitude. The
Osceola Lahar
The Osceola Mudflow, also known as the Osceola Lahar, was a lahar in the U.S. state of Washington (state), Washington that descended from the summit and northeast slope of Mount Rainier during a period of eruptions about 5,600 years ago. It tr ...
produced by
Mount Rainier
Mount Rainier (), indigenously known as Tahoma, Tacoma, Tacobet, or təqʷubəʔ, is a large active stratovolcano in the Cascade Range of the Pacific Northwest, located in Mount Rainier National Park about south-southeast of Seattle. With a s ...
in modern-day
Washington
Washington commonly refers to:
* Washington (state), United States
* Washington, D.C., the capital of the United States
** A metonym for the federal government of the United States
** Washington metropolitan area, the metropolitan area centered o ...
some 5600 years ago resulted in a wall of mud deep in the
White River canyon and covered an area of over , for a total volume of .
A debris-flow lahar can erase virtually any structure in its path, while a hyperconcentrated-flow lahar is capable of carving its own pathway, destroying buildings by undermining their foundations.
A hyperconcentrated-flow lahar can leave even frail huts standing, while at the same time burying them in mud,
which can harden to near-concrete hardness. A lahar's viscosity decreases the longer it flows and can be further thinned by rain, producing a
quicksand
Quicksand is a colloid consisting of fine granular material (such as sand, silt or clay) and water. It forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates a liquefied soil that los ...
-like mixture that can remain fluidized for weeks and complicate search and rescue.
Lahars vary in speed. Small lahars less than a few metres wide and several centimetres deep may flow a few metres per second. Large lahars hundreds of metres wide and tens of metres deep can flow several tens of metres per second (22 mph or more), much too fast for people to outrun.
On steep slopes, lahar speeds can exceed .
A lahar can cause catastrophic destruction along a potential path of more than .
Lahars from the 1985
Nevado del Ruiz
The Nevado del Ruiz (), also known as La Mesa de Herveo ( en, Mesa of Herveo, the name of the nearby town) is a volcano on the border of the departments of Caldas and Tolima in Colombia, about west of the capital city Bogotá. It is a strat ...
eruption in
Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
caused the
Armero tragedy
The Armero tragedy ( es, Tragedia de Armero, links=no ) occurred following the eruption of the Nevado del Ruiz stratovolcano in Tolima, Colombia, on November 13, 1985. The volcano's eruption after 69 years of dormancy caught nearby towns unawa ...
, burying the city of
Armero
Armero is a municipality in the Tolima Department, Colombia. According to the National Department of Statistics of Colombia, 12,852 lived in the town in 2005. Its median temperature is 27 °C. It was founded in 1895, but was not officia ...
under of mud and debris and killing an estimated 23,000 people. A lahar caused New Zealand's
Tangiwai disaster
The Tangiwai disaster occurred at 10:21 p.m. on 24 December 1953 when a railway bridge over the Whangaehu River collapsed beneath an express passenger train at Tangiwai, North Island, New Zealand. The locomotive and the first six carriage ...
,
where 151 people died after a Christmas Eve express train fell into the
Whangaehu River
The Whangaehu River is a large river in central North Island of New Zealand. Its headwaters are the crater lake of Mount Ruapehu on the central plateau, and it flows into the Tasman Sea eight kilometres southeast of Whanganui. Water is diverted ...
in 1953. Lahars have caused 17% of volcano-related deaths between 1783 and 1997.
Trigger mechanisms
![MSH80 mudline muddy river with USGS scientist 10-23-80](https://upload.wikimedia.org/wikipedia/commons/1/16/MSH80_mudline_muddy_river_with_USGS_scientist_10-23-80.jpg)
Lahars have several possible causes:
*
Snow
Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes.
It consists of frozen crystalline water throughout ...
and
glacier
A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its Ablation#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...
s can be melted by
lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...
or
pyroclastic surge
A pyroclastic surge is a fluidised mass of turbulent gas and rock fragments that is ejected during some volcanic eruptions. It is similar to a pyroclastic flow but it has a lower density or contains a much higher ratio of gas to rock, which makes ...
s during an eruption.
* Lava can erupt from open vents and mix with wet soil, mud or snow on the slope of the volcano making a very viscous, high energy lahar. The higher up the slope of the volcano, the more
gravitational potential energy
Gravitational energy or gravitational potential energy is the potential energy a massive object has in relation to another massive object due to gravity. It is the potential energy associated with the gravitational field, which is released (conv ...
the flows will have.
* A
flood
A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrol ...
caused by a glacier,
lake breakout
Lake breakout is the collapse of a lake, usually of high-altitude. High-altitude lakes tend to form in volcanic craters – where they are called crater lakes – or in valleys dammed as the result of earthquakes or glacial or volcanic depo ...
, or heavy rainfalls can generate lahars, also called
glacier run
A glacial lake outburst flood (GLOF) is a type of outburst flood caused by the failure of a dam containing a glacial lake. An event similar to a GLOF, where a body of water contained by a glacier melts or overflows the glacier, is called a jö ...
or
jökulhlaup
A jökulhlaup ( ) (literally "glacial run") is a type of glacial outburst flood. It is an Icelandic term that has been adopted in glaciological terminology in many languages.
It originally referred to the well-known subglacial outburst flood ...
.
* Water from a
crater lake
Crater Lake (Klamath language, Klamath: ''Giiwas'') is a volcanic crater lake in south-central Oregon in the western United States. It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity. The ...
can combine with volcanic material in an eruption.
* Heavy rainfall can mobilize unconsolidated pyroclastic deposits.
In particular, although lahars are typically associated with the effects of volcanic activity, lahars can occur even without any current volcanic activity, as long as the conditions are right to cause the collapse and movement of mud originating from existing
volcanic ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used t ...
deposits.
* Snow and glaciers can melt during periods of mild to hot weather.
*
Earthquakes
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...
underneath or close to the volcano can shake material loose and cause it to collapse, triggering a lahar avalanche.
*
Rainfall
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...
can cause the still-hanging slabs of solidified mud to come rushing down the slopes at a speed of more than , causing devastating results.
Places at risk
![Galunggung lahar](https://upload.wikimedia.org/wikipedia/commons/4/41/Galunggung_lahar.jpg)
Several mountains in the world – including
Mount Rainier
Mount Rainier (), indigenously known as Tahoma, Tacoma, Tacobet, or təqʷubəʔ, is a large active stratovolcano in the Cascade Range of the Pacific Northwest, located in Mount Rainier National Park about south-southeast of Seattle. With a s ...
in the United States,
Mount Ruapehu
Mount Ruapehu (; ) is an active stratovolcano at the southern end of the Taupō Volcanic Zone and North Island volcanic plateau in New Zealand. It is northeast of Ohakune and southwest of the southern shore of Lake Taupō, within the Tongari ...
in New Zealand, and
Merapi and
Galunggung
Mount Galunggung (Indonesian: ''Gunung Galunggung'', formerly spelled ''Galoen-gong'') is an active stratovolcano in West Java, Indonesia, around southeast of the West Java provincial capital, Bandung (or around to the east of the West Java t ...
in Indonesia – are considered particularly dangerous due to the risk of lahars. Several towns in the
Puyallup River
The Puyallup River ( ) is a river in the U.S. state of Washington (state), Washington. About long, it is formed by glaciers on the west side of Mount Rainier. It flows generally northwest, emptying into Commencement Bay, part of Puget Sound. The ...
valley in Washington state, including
Orting
Orting is a city in Pierce County, Washington, United States. The population was 9,041 at the 2020 census.
History
The first recorded claims for land in Orting were made in 1854 by William Henry Whitesell, Thomas Headley, Daniel Lane, and D ...
, are built on top of lahar deposits that are only about 500 years old. Lahars are predicted to flow through the valley every 500 to 1,000 years, so Orting,
Sumner,
Puyallup,
Fife
Fife (, ; gd, Fìobha, ; sco, Fife) is a council area, historic county, registration county and lieutenancy area of Scotland. It is situated between the Firth of Tay and the Firth of Forth, with inland boundaries with Perth and Kinross (i ...
, and the Port of
Tacoma face considerable risk. The
USGS
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...
has set up
lahar warning sirens in
Pierce County, Washington
Pierce County is a county in the U.S. state of Washington. As of the 2020 census, the population was 921,130, up from 795,225 in 2010, making it the second-most populous county in Washington, behind King County, and the 60th-most populous ...
, so that people can flee an approaching debris flow in the event of a Mount Rainier eruption.
A lahar
warning system
Warning system is any system of biological or technical nature deployed by an individual or group to inform of a future danger. Its purpose is to enable the deployer of the warning system to prepare for the danger and act accordingly to mitigat ...
has been set up at
Mount Ruapehu
Mount Ruapehu (; ) is an active stratovolcano at the southern end of the Taupō Volcanic Zone and North Island volcanic plateau in New Zealand. It is northeast of Ohakune and southwest of the southern shore of Lake Taupō, within the Tongari ...
by the
New Zealand Department of Conservation
The Department of Conservation (DOC; Māori: ''Te Papa Atawhai'') is the public service department of New Zealand charged with the conservation of New Zealand's natural and historical heritage.
An advisory body, the New Zealand Conservation Au ...
and hailed as a success after it successfully alerted officials to an impending lahar on 18 March 2007.
Since mid-June 1991, when violent eruptions triggered
Mount Pinatubo
Mount Pinatubo is an active stratovolcano in the Zambales Mountains, located on the tripoint boundary of the Philippine provinces of Zambales, Tarlac and Pampanga, all in Central Luzon on the northern island of Luzon. Its eruptive history w ...
's first lahars in 500 years, a system to monitor and warn of lahars has been in operation. Radio-telemetered rain gauges provide data on rainfall in lahar source regions, acoustic flow monitors on stream banks detect ground vibration as lahars pass, and manned watchpoints further confirm that lahars are rushing down Pinatubo's slopes. This system has enabled warnings to be sounded for most but not all major lahars at Pinatubo, saving hundreds of lives.
Physical preventative measures by the
Philippine government
The Government of the Philippines ( fil, Pamahalaan ng Pilipinas) has three interdependent branches: the legislative, executive, and judicial branches. The Philippines is governed as a unitary state under a presidential representative and d ...
were not adequate to stop over of mud from flooding many villages around Mount Pinatubo from 1992 through 1998.
Scientists and governments try to identify areas with a high risk of lahars based on historical events and
computer model
Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be deter ...
s. Volcano scientists play a critical role in effective hazard education by informing officials and the public about realistic hazard probabilities and scenarios (including potential magnitude, timing, and impacts); by helping evaluate the effectiveness of proposed risk-reduction strategies; by helping promote acceptance of (and confidence in) hazards information through participatory engagement with officials and vulnerable communities as partners in risk reduction efforts; and by communicating with emergency managers during extreme events. An example of such a model is
TITAN2D
TITAN2D is a geoflow simulation software application, intended for geological researchers. It is distributed as free software.
Overview
TITAN2D is a free software application developed by the Geophysical Mass Flow Group at the State University o ...
. These models are directed towards future planning: identifying low-risk regions to place community buildings, discovering how to mitigate lahars with dams, and constructing evacuation plans.
Examples
Nevado del Ruiz
In 1985, the volcano
Nevado del Ruiz
The Nevado del Ruiz (), also known as La Mesa de Herveo ( en, Mesa of Herveo, the name of the nearby town) is a volcano on the border of the departments of Caldas and Tolima in Colombia, about west of the capital city Bogotá. It is a strat ...
erupted in central Colombia. As
pyroclastic flows
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...
erupted from the
volcano's crater, they melted the mountain's glaciers, sending four enormous lahars down its slopes at . The lahars picked up speed in
gullies
A gully is a landform created by running water, mass movement, or commonly a combination of both eroding sharply into soil or other relatively erodible material, typically on a hillside or in river floodplains or terraces. Gullies resemble lar ...
and coursed into the six major rivers at the base of the volcano; they engulfed the
town of Armero, killing more than 20,000 of its almost 29,000 inhabitants.
Casualties in other towns, particularly
Chinchiná, brought the overall death toll to over 25,000. Footage and photographs of
Omayra Sánchez
Omayra Sánchez Garzón (August 28, 1972 – November 16, 1985) was a Colombian girl trapped and killed by a landslide when she was 13 years old.
The landslide was caused by the 1985 eruption of the volcano Nevado del Ruiz in Armero, ...
, a young victim of the
tragedy
Tragedy (from the grc-gre, τραγῳδία, ''tragōidia'', ''tragōidia'') is a genre of drama based on human suffering and, mainly, the terrible or sorrowful events that befall a main character. Traditionally, the intention of tragedy ...
, were published around the world. Other photographs of the lahars and the impact of the disaster captured attention worldwide and led to controversy over the degree to which the Colombian government was responsible for the disaster.
Mount Pinatubo
![River valley filled in by pyroclastic flows, Mt](https://upload.wikimedia.org/wikipedia/commons/e/e5/River_valley_filled_in_by_pyroclastic_flows%2C_Mt._Pinatubo.jpg)
Lahars caused most of the deaths of the
1991 eruption of Mount Pinatubo. The initial eruption killed six people, but the lahars killed more than 1500. The eye of
Typhoon Yunya passed over the volcano during its eruption on 15 June 1991, and the resulting rain triggered the flow of
volcanic ash
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used t ...
, boulders, and water down rivers surrounding the volcano.
Angeles City
, anthem = Himno ning Angeles (Angeles Hymn)
, subdivision_type3 = District
, subdivision_name3 =
, established_title = Settled
, established_date = 1796
, established_title1 = Chartere ...
in
Pampanga
Pampanga, officially the Province of Pampanga ( pam, Lalawigan ning Pampanga; tl, Lalawigan ng Pampanga ), is a province in the Central Luzon region of the Philippines. Lying on the northern shore of Manila Bay, Pampanga is bordered by Tarlac ...
and neighbouring cities and towns were damaged by lahars when Sapang Balen Creek and the Abacan River became channels for mudflows and carried them to the heart of the city and surrounding areas.
Over of mud inundated and damaged the towns of
Castillejos
Castillejos, officially the Municipality of Castillejos ( ilo, Ili ti Castillejos; tl, Bayan ng Castillejos), is a 3rd class municipality in the province of Zambales, Philippines. According to the 2020 census, it has a population of 67,889 peopl ...
,
San Marcelino
San Marcelino, officially the Municipality of San Marcelino ( ilo, Ili ti San Marcelino; tgl, Bayan ng San Marcelino), is a 1st class municipality in the province of Zambales, Philippines. According to the 2020 census, it has a population of 37 ...
and
Botolan in
Zambales
Zambales, officially the Province of Zambales ( fil, Lalawigan ng Zambales; ilo, Probinsia ti Zambales; Pangasinan: ''Luyag/Probinsia na Zambales''; xsb, Probinsya nin Zambales), is a province in the Philippines located in the Central Luzon re ...
,
Porac
Porac, officially the Municipality of Porac ( pam, Balen ning Porac; fil, Bayan ng Porac), is a 1st class municipality in the province of Pampanga, Philippines. According to the 2020 census, it has a population of 140,751 people.
The Subic–Cl ...
and
Mabalacat
Mabalacat, officially the City of Mabalacat ( pam, Lakanbalen ning Mabalacat; fil, Lungsod ng Mabalacat), is a 3rd class component city in the province of Pampanga, Philippines. According to the 2020 census, it has a population of 293,244 people ...
in
Pampanga
Pampanga, officially the Province of Pampanga ( pam, Lalawigan ning Pampanga; tl, Lalawigan ng Pampanga ), is a province in the Central Luzon region of the Philippines. Lying on the northern shore of Manila Bay, Pampanga is bordered by Tarlac ...
,
Tarlac City
Tarlac City, officially the City of Tarlac ( pam, Lakanbalen ning Tarlac; pag, Siyudad na Tarlac; ilo, Siudad ti Tarlac; fil, Lungsod ng Tarlac ), is a 1st class component city and capital of the province of Tarlac, Philippines. According to ...
,
Capas
Capas, officially the Municipality of Capas ( pam, Balen ning Capas;
tgl, Bayan ng Capas), is a 1st class municipality in the province of Tarlac, Philippines, and one of the richest towns in the province. The town also consists of numerous su ...
,
Concepcion and
Bamban in
Tarlac
Tarlac, officially the Province of Tarlac ( pam, Lalawigan ning Tarlac; pag, Luyag/Probinsia na Tarlac; ilo, Probinsia ti Tarlac; tgl, Lalawigan ng Tarlac; ), is a landlocked province in the Philippines located in the Central Luzon region. It ...
.
[ The Bamban Bridge on the MacArthur Highway, a major north–south transportation route, was destroyed, and temporary bridges erected in its place were inundated by subsequent lahars.]
On the morning of 1 October 1995, pyroclastic material which clung to the slopes of Pinatubo and surrounding mountains rushed down because of heavy rain, and turned into an lahar. This mudflow killed at least 100 people in Barangay Cabalantian in Bacolor
Bacolor, officially the Municipality of Bacolor ( pam, Balen ning Bakúlud; tgl, Bayan ng Bacolor), is a 3rd class municipality in the province of Pampanga, Philippines. According to the 2020 census, it has a population of 48,066 people.
Bacolor ...
. The Philippine government under President Fidel V. Ramos
Fidel Valdez Ramos (, ; March 18, 1928 – July 31, 2022), popularly known as FVR and Eddie Ramos, was a Filipino general and politician who served as the 12th president of the Philippines from 1992 to 1998. He was the only career military ...
ordered the construction of the FVR Mega Dike in an attempt to protect people from further mudflows.
Typhoon Reming
Typhoon Durian, known in the Philippines as Typhoon Reming, was a deadly tropical cyclone that wreaked havoc in the Philippines and later crossed the Malay Peninsula in late November 2006, causing massive loss of life when mudflows from the May ...
triggered additional lahars in the Philippines in 2006.
See also
* Volcanic hazards
A volcanic hazard is the probability a volcano, volcanic eruption or related geophysical event will occur in a given geographic area and within a specified window of time. The risk that can be associated with a volcanic hazard depends on the proxi ...
* Mass wasting
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 ...
* Polder
A polder () is a low-lying tract of land that forms an artificial hydrological entity, enclosed by embankments known as dikes. The three types of polder are:
# Land reclaimed from a body of water, such as a lake or the seabed
# Flood plains s ...
* Land reclamation
Land reclamation, usually known as reclamation, and also known as land fill (not to be confused with a waste landfill), is the process of creating new land from oceans, seas, riverbeds or lake beds. The land reclaimed is known as reclamati ...
References
External links
Schools page about lahars and pyroclastic flows
USGS web page about lahars
Mount Rainier, Washington
USGS fact sheet – "Mount Rainier – Living Safely With a Volcano in Your Back Yard"
{{Natural disasters
Volcanism
Geological hazards