Define landslide | Dictionary and Thesaurus

Time 2020-11-11 19:03:52

Web Name: Define landslide | Dictionary and Thesaurus

WebSite: http://landslide.askdefine.com

ID:112680

Keywords:

landslide,Define,Dictionary,

Description:

Dutch: lawine orFinnish: maanvyöry,maanvyörymäItalian: frana ,smottamento ,slavinaJapanese: 地滑り(じすべり); 山崩れ(やまくずれ), 山津波(やまつなみ, yamatsunami)Russian: оползень (ópolz'en')Slovene: plazSee alsoWeather: avalanche, earthquake, mudslidePolitics: shoo-inExtensive Definitionmain Causesof landslides Landslides are caused when the stability ofa slope changes from a stable to an unstable condition. Achange in the stability of a slope can be caused by a number offactors, acting together or alone:Natural causes:groundwaterpressure acting to destabilize the slopeLoss or absence of vertical vegetative structure, soilnutrients, and soilstructure.erosion of the toeof a slope by rivers orocean wavesweakening of a slope through saturation by snowmelt, glaciers melting, or heavyrainsearthquakesadding loads to barely-stable slopesearthquake-caused liquefactiondestabilizing slopes (see Hope Slide)volcaniceruptionsHuman causes:vibrations frommachinery or trafficblastingearthwork whichalters the shape of a slope, or which imposes new loads on anexisting slopein shallow soils, theremoval of deep-rootedvegetation that bindscolluvium to bedrockConstruction, agricultural, or forestry activities which changethe amount of water which infiltrates into the soil.Types of landslidesync LandslideclassificationDebris flowSlope material that becomes saturated with water may develop into a debris flowor mud flow. Theresulting slurry of rock andmud may pick up trees, houses, and cars, thus blocking bridges and tributaries causing flooding along its path.Debris flow is often mistaken for flash flood,but they are entirely different processes.Muddy-debris flows in alpine areas cause severe damageto structures and infrastructure and often claim human lives.Muddy-debris flows can start as a result of slope-related factors,and shallow landslides can dam stream beds,provoking temporary water blockage. As the impoundments fail, a"domino effect" may becreated, with a remarkable growth in the volume of the flowingmass, which takes up the debris in the stream channel. Thesolid-liquid mixture can reach densities of up to2tons/m³ and velocities of up to 14m/s (Chiarleand Luino, 1998; Arattano, 2003). These processes normally causethe first severe road interruptions, due not only to depositsaccumulated on the road (from several cubic metres to hundreds ofcubic metres), but in some cases to the complete removal of bridgesor roadways or railways crossing the stream channel. Damage usuallyderive from a common underestimation of mud-debris flows: in thealpine valleys, for example, bridges are frequently destroyed bythe impact force of the flow because their span is usuallycalculated only for a water discharge. For a small basin in theItalian Alps (area = 1.76 km²) affected by a debris flow, Chiarleand Luino (1998) estimated a peak discharge of 750 m3/s for asection located in the middle stretch of the main channel. At thesame cross section, the maximum foreseeable water discharge (byHEC-1), was 19 m³/s, a value about 40 times lower than thatcalculated for the debris flow that occurred.Earth flowEarthflows aredownslope, viscous flows of saturated, fine-grained materials, thatmove at any speed from slow to fast. Typically, they can move atspeeds from .17 to 20 km/h. Though these are a lot like mudflows, overall they areslower moving and are covered with solid material carried along byflow from within. They are different from fluid flows in that theyare more rapid. Clay, fine sand and silt, and fine-grained,pyroclastic material are all susceptible to earthflows. Thevelocity of the earthflow is all dependent on how much watercontent is in the flow itself: if there is more water content inthe flow, the higher the velocity will be.These flows usually begin when the pore pressuresin a fine-grained mass increase until enough of the weight of thematerial is supported by pore water to significantly decrease theinternal shearing strength of the material. This thereby creates abulging lobe which advances with a slow, rolling motion. As theselobes spread out, drainage of the mass increases and the marginsdry out, thereby lowering the overall velocity of the flow. Thisprocess causes the flow to thicken. The bulbous variety ofearthflows are not that spectacular, but they are much more commonthan their rapid counterparts. They develop a sag at their headsand are usually derived from the slumping at the source.Earthflows occur much more during periods of highprecipitation, which saturates the ground and adds water to theslope content. Fissures develop during the movement of clay-likematerial creates the intrusion of water into the earthflows. Waterthen increases the pore-water pressure and reduces the shearingstrength of the material.SturzstromA sturzstrom is a rare, poorlyunderstood type of landslide, typically with a long run-out. Oftenvery large, these slides are unusually mobile, flowing very farover a low angle, flat, or even slightly uphill terrain. They aresuspected of "riding" on a blanket of pressurized air, thusreducing friction with the current underlying surface.Shallow landslideLandslide in which the sliding surface is locatedwithin the soil mantle orweathered bedrock (typically to a depthfrom few decimetres to some metres). They usually include debrisslides, debris flow,and failures of road cut-slopes. Landslides occurring as singlelarge blocks of rock moving slowly down slope are sometimes calledblock glides.Shallow landslides can often happen in areas thathave slopes with high permeable soils on top of low permeablebottom soils. The low permeable, bottom soils trap the water in theshallower, high permeable soils creating high water pressure in thetop soils. As the top soils are filled with water and become heavy,slopes can become very unstable and slide over the low permeablebottom soils. Say there is a slope with silt and sand as its topsoil and bedrock as its bottom soil. During an intense rainstorm,the bedrock will keep the rain trapped in the top soils of silt andsand. As the topsoil becomes saturated and heavy, it can start toslide over the bedrock and become a shallow landslide. R. H.Campbell did a study on shallow landslides on Santa Cruz IslandCalifornia. He notes that if permeability decreases with depth, aperched water table may develop in soils at intense precipitation.When pore water pressures are sufficent to reduce effective normalstress to a critical level, failure occurs.Deep-seated landslideLandslides in which the slidingsurface is mostly deeply located below the maximum rooting depth oftrees (typically to depths greater than ten metres). Deep-seatedlandslides usually involve deep regolith, weathered rock,and/or bedrock andinclude large slope failure associated with translational,rotational, or complex movement.Related phenomenaAn avalanche,similar in mechanism to a landslide, involves a large amount ofice, snow and rock falling quickly down the side of a mountain.A pyroclasticflow is caused by a collapsing cloud of hot ash, gas androcks from a volcanic explosion that moves rapidly down an eruptingvolcano.Historical landslidesThe Agulhas slide, ca. 20,000 km³, off SouthAfrica, post-Pliocene in age,the largest so far describedThe StoreggaSlide, Norway, ca. 3,500km³, ca. 8,000 years agoThe Ruatoria debris avalanche, off North IslandNewZealand, ca. 3,000 km³ in volume, 170,000 years agohttp://www.agu.org/pubs/crossref/2001/2001JB900004.shtml.Landslide which moved HeartMountain to its current location, ParkCounty, Wyoming, the largest ever discovered on landCliff landslip of the Undercliff nearLymeRegis, Dorset, England, on 24December 1839The Cap Diamant Québecrockslide on September 19, 1889FrankSlide, Turtle Mountain, Alberta, Canada, on 29 AprilThe Riñihuazolandslide in Chile after theGreatChilean Earthquake, on 22 May 1960MonteToc landslide (260 millions cubic metres) falling into theVajontDam basin in Italy, causing a megatsunami and about 2000casualties, on October 9,1963The 1966 AberfandisasterSaint-Jean-Vianney,Quebec,Canada.Small village near Saguenay river destroyed in May 1971.Landslides associated with the Mount St.Helens eruption on May 18, 1980.Thistle,Utah on 14 April 1983The Mameyes Disaster - Ponce,Puerto Rico on October 7,1985Val Polalandslide during Valtellinadisaster (1987) ItalyThredbolandslide, Australia on30 July,1997The Vargastragedy, due to heavy rains in Vargas State,Venezuela, onDecember, 1999, causing tens ofthousands of casualties.Payatas, Manila garbage slideon 11July, 2000.Southern Leyte landslide in the Philippines on17February, 2006Devil'sSlide, an ongoing landslide in San Mateo County, California2007Chittagong mudslide, in Chittagong,Bangladesh, onJune 11,2007.Extraterrestrial landslidesEvidence of past landslides has been detected onmany bodies in the solar system, but since most observations aremade by probes that only observe for a limited time and most bodiesin the solar system appear to be geologically inactive not manylandslides are known to have happened in recent times. Both Venusand Mars have been subject to long-term mapping by orbitingsatellites, and examples of recent landslides have been observed onboth.See alsoAutomatic Deformation Monitoring SystemDeformationmonitoringGeotechnicsGeotechnicalengineeringLandslidemitigationMasswastingSlopestabilityLandslidedamReferencesExternal linksUnited States GeologicalSurvey siteEuropeanSoil Portal, LandslidesBritishColumbia government landslide informationSlide!, aprogram on B.C.'s Knowledge Network, with video clipsGeoscience Australia Fact Sheet http://www.ga.gov.au/urban/factsheets/landslide.jsp/Picturesof Slope FailureJTC1 JointInternational Technical Committee on Landslides and EngineeredSlopeslandslide in Bengali: ভূমিধ্বসlandslide in Bulgarian: Свлачищеlandslide in German: Erdrutschlandslide in Spanish: Corrimiento detierralandslide in Esperanto: Terglitolandslide in French: Glissement de terrainlandslide in Indonesian: Tanah longsorlandslide in Icelandic: Berghlauplandslide in Italian: Franalandslide in Lithuanian: Nuošliaužalandslide in Malay (macrolanguage): Tanahruntuhlandslide in Dutch: Aardverschuivinglandslide in Japanese: 地すべりlandslide in Polish: Osuwiskolandslide in Portuguese: Deslizamento deterralandslide in Romanian: Alunecare de terenlandslide in Quechua: Lluqllalandslide in Russian: Оползеньlandslide in Simple English: Landslidelandslide in Slovak: Zosuv svahulandslide in Finnish: Maanvyörylandslide in Swedish: Jordskredlandslide in Turkish: Heyelanlandslide in Ukrainian: Зсув ґрунтуlandslide in Chinese: 山崩Synonyms, Antonyms and RelatedWordsCadmean victory, KO, Pyrrhic victory, abundance, affluence, ample sufficiency,ampleness, amplitude, ascendancy, avalanche, bonanza, bountifulness, bountiousness, bumpercrop, championship,coast, conquest, copiousness, count, deluge, easy victory, electionreturns, embarras de richesses, enough, extravagance, extravagancy, exuberance, fertility, flood, flow, foison, full measure, fullness, generosity, generousness, glide, glissade, glissando, grand slam, greatabundance, great plenty, gush, inundation, knockout, landslide victory,landslip, lavishness, liberality, liberalness, lots, luxuriance, mastery, maximum, money to burn, moralvictory, more than enough, much, myriad, myriads, numerousness, officialcount, opulence,opulency, outpouring, overabundance, overaccumulation,overbounteousness,overcopiousness,overdose, overflow, overlavishness, overluxuriance, overmeasure, overmuchness, overnumerousness,overplentifulness,overplenty, overpopulation, overprofusion, oversufficiency,oversupply, picnic, plenitude, plenteousness, plentifulness, plenty, plethora, poll, prevalence, prodigality, productiveness, profuseness, profusion, pushover, quantities, recount, redundancy, repleteness, repletion, returns, rich harvest, richvein, richness,riot, riotousness, runawayvictory, scads, shower, sideslip, skid, slide, slip, slippage, slither, snowslide, snowslip, spate, stream, subdual, subduing, subsidence, substantiality, substantialness,success, superabundance, superflux, teemingness, tidal wave,total victory, triumph,victory, walkaway, walkover, wealth, win, winning, winningstreak

TAGS:landslide Define Dictionary 

<<< Thank you for your visit >>>

Hot Websites