ch9 flashcards
(24 cards)
mass wasting
The downslope movement of soil, rock, and debris under the influence of gravity, occurring with or without a trigger such as water saturation, earthquakes, or human activity
mudflow
A rapidly moving flow of water-saturated mud, soil, and sediment, often triggered by heavy rainfall or volcanic eruptions (lahars)
debris avalanche
A very fast, turbulent mass wasting event involving a large volume of rocks, soil, and debris racing downslope
rockfall
The free fall of individual rocks or rock fragments from a steep slope or cliff, resulting in an accumulation of angular debris at the base
creep (soil creep)
The very slow, almost imperceptible downslope movement of soil and regolith, often indicated by bent tree trunks or tilted utility poles
solifluction
The slow flow of waterlogged soil downslope, especially common in regions with permafrost where freeze-thaw cycles aid movement
earthflow-slump
A slower mass movement where water-saturated soil or weathered material moves as a thick, viscous fluid (earthflow) and may form a rotational slide (slump) with a curved slip surface
debris
Unconsolidated fragments of rock, soil, and other loose material involved in mass wasting processes
debris flow
A rapid mass movement of a fluid mixture of rocks, soil, and water, similar to a mudflow but containing larger and more angular fragments
flow (mass wasting)
A type of mass wasting in which material moves downslope as a viscous fluid, deforming continuously and often supported by water or air
fall
A type of mass wasting in which material detaches from a steep slope or cliff and free-falls, often forming talus piles below
landslide
A general term for any rapid downslope movement of rock, soil, or debris. It can encompass falls, slides, and flows
mud
A fine-grained mixture of silt, clay, and water that can liquefy and flow downslope as a mudflow
relief
The elevation difference in a particular area; high relief with steep slopes is more prone to mass wasting events
rock avalanche
A very large and extremely fast flow of shattered rock fragments racing downslope, often triggered by earthquakes or volcanic eruptions
rockslide
A mass wasting event where a layer of rock detaches and slides downslope along a planar surface, maintaining some coherence
rotational slide (slump)
A type of slide where material moves down a curved slip surface, causing the surface of the displaced mass to rotate backward
slide
A mass wasting process in which material moves downslope along a distinct surface or bedding plane, often maintaining some internal structure
slump
A type of rotational slide where a block of earth or rock moves downslope along a concave, curved surface, creating a stepped, back-tilted landform
soil
The upper layer of Earth’s surface composed of weathered rock, minerals, organic matter, and air, which can be mobilized in mass wasting
permafrost
Ground that remains frozen for two or more consecutive years, common in polar regions; thawing permafrost can enhance solifluction
talus
A sloping accumulation of angular rock fragments at the base of a cliff, formed by rockfall and other mass wasting processes
translational slide
A landslide that moves downslope along a nearly planar surface, often following bedding planes, faults, or joints in the rock
hummocky
Describes a landscape of irregular, lumpy mounds and hollows commonly formed by mass wasting or glacial deposits, giving uneven terrain
