What factors led to the massive rockslide at Gros Ventre Wyoming? A combination of three factors caused the rock slide: 1)
heavy rains and rapidly melting snow saturated the Tensleep Sandstone causing the underlying shale of the Amsden Formation to lose its shear strength
, 2) the Gros Ventre River cut through the sandstone creating an oversteepened slope, and 3) soil on top of the …
Which is a factor of influence on when and what type of mass wasting occurs?
Mass wasting is influenced by
slope, material strength, water content, and amount of vegetation
. Mass wasting can be triggered by storms, earthquakes, eruptions, and human activity. Fall, slide, flow, and creep are the main categories of mass wasting mechanisms.
How did the debris from the Gros Ventre landslide of 1925 lead to another disaster in the same region in 1927?
How did the debris from the Gros Ventre Landslide of 1925 lead to another disaster in the same region in 1927?
The debris blocked the river, creating a lake that later burst.
Which of those processes rock fall rock slide or slump occurred in Gros Ventre near Jackson Hole WY in 1925?
The landslide occurred on June 23, 1925, following melt from a heavy snowpack, several weeks of heavy rain, and
earthquake tremors
in the area.
Which would be the most likely location for a rockslide to occur?
Which would be the most likely location for a rockslide to occur?
Inclined strata with joints and fractures parallel to the slope face
.
The Gros Ventres are
an Algonquian-speaking people from the area of the Great Plains between the Missouri River, Montana, and the Saskatchewan River in the Canadian Prairies
.
It could be rapid snowmelt, intense rainfall, earthquake shaking, volcanic eruption, storm waves, rapid-stream erosion, or human activities, such as grading a new road.
Increased water content within the slope
is the most common mass-wasting trigger.
causes of Mass Movements: Gravity: the most important factor in causing mass movements. Water: adds weight to the slopes and reduces friction between the soil particles. Undercutting of a slope: by natural processes, such as streams.
- Rockfall. Bits of rock fall off the cliff face, usually due to freeze-thaw weathering.
- Mudflow. Saturated soil (soil filled with water) flows down a slope.
- Landslide. Large blocks of rock slide downhill.
- Rotational slip. Saturated soil slumps down a curved surface.
Types of Mass Movement:
Creep; Fall, Slip, Flow; Solifluction; Rock Glaciers; Slumping (Earthflow); Mudflow (lahar); Debris Flow, Debris Slide, Debris Avalanche; Rockslide; Rockfall; Debris Fall
. Deposits: Collurium; Talus.
How did the underlying geology contribute to the Gros Ventre Landslide of 1925?
Rains saturated the sandstone and clay that make up the slope.
Which event can cause slumps, landslides, and mudflows to occur?
A loose pile of rocks and soil travels in a single large mass
. The mass moves a short distance downhill.
A slump is a form of mass wasting that occurs
when a coherent mass of loosely consolidated materials or a rock layer moves a short distance down a slope
. Movement is characterized by sliding along a concave-upward or planar surface.
| Question Answer | How do the strength and cohesion of clay-rich regolith or soil change with the addition of water? Water lowers the strength and cohesion | ________ involves movement on a zone of compressed air. A rock avalanche | Of the following, which one would most likely be triggered by an earthquake? rock avalanche |
|---|
A rockslide is a type of landslide caused by
rock failure
in which part of the bedding plane of failure passes through compacted rock and material collapses en masse and not in individual blocks. Note that a rockslide is similar to an avalanche because they are both slides of debris that can bury a piece of land.
Landslides are caused by
disturbances in the natural stability of a slope
. They can accompany heavy rains or follow droughts, earthquakes, or volcanic eruptions. Mudslides develop when water rapidly accumulates in the ground and results in a surge of water-saturated rock, earth, and debris.
The Gros Ventre Tribe of Montana is a tribe of the Northern Plains Indigenous group, located in
North central Montana
. They live on the Fort Belknap Reservation, which is shared with the Assiniboine tribe. The Gros Ventre live primarily in the south end of the reservation, near the Little Rocky Mountains.
mass wasting erosion can be triggered when
heavy rains or snow-melt saturate the surface
. when pore spaces become filled with water (saturated) the cohesion between grains is destroyed allowing them to slide past one another.
Debris flows are defined as mass‐wasting events in which turbulence occurs throughout the mass. Varieties of these are called
earthflows, mudflows, and debris avalanches
.
