3.0 Crust of the Earth: Erosion and Mass Wasting

These flashcards cover the essential concepts of erosion, mass wasting, fluid dynamics, and the pathways of sediment transport, aimed at helping students understand and recall key information for their exam.

Weathering is the process involved in the __ of rock.

breakdown

Erosion is the set of processes whereby __ is picked up and transported from one place to another.

regolith

Fluids are substances which change their __ easily under their own weight.

shape

Two important parameters of fluids are density and __.

viscosity

In fluid mechanics, a __ applies shear stress to materials.

shear force

Laminar flows consist of different streamlines that are __ to each other.

parallel

In turbulent flows, streamlines __ and turn, showing significant movement in multiple directions.

twist

Reynolds number helps determine whether flow is __ or turbulent.

laminar

Water transport of material is the most __ of transport mechanisms.

significant

Sediments deposited by water action in river valleys are termed __.

alluvial

Wind transports sediments referred to as __ sediments or deposits.

eolian

Chatter marks are crescent-shaped gouges formed as rock fragments are dragged across __.

bedrock

Moving particles under __ down a slope is the simplest mechanism of sediment transport.

gravity

The angle of __ varies significantly based on particle size and shape.

repose

Creep is the slow deformation of soil where the upper layers move down the slope faster than the __ layers.

lower

A __ is characterized by incoherent material that moves chaotically and disorganized, as a fluid flows.

flow

Debris flow contains material coarser than sand and travels at rates from a few __ per hour to tens of kilometers per hour.

kilometers

Mudflows contain large quantities of __, moving at higher speeds than earthflows or debris flows.

water

The __ in landslides can create unstable slopes, potentially leading to floods.

nature of slope materials

Highway roadcuts and open-pit mining can lead to __ issues.

stability

To stabilize a slope, methods can include reducing the slope __ or the load on the slope.

angle

Ground covers or other vegetation may be used to stabilize exposed __ soil.

near-surface

Rock bolts are used for stabilizing __ slopes and rockslides.

rocky

Using subsurface drainage can help decrease water content or __ pressure in soils.

pore

An earthflow involves fine-grained materials traveling at speeds of a few __ per hour.

kilometers

The surface of a slump is typically relatively __, indicating a less disturbed top layer.

undisturbed

Gravity-driven mass wasting events, such as rockfalls, typically travel only __ distances compared to other types.

shorter

Water can contribute to mass movements by creating __ in slopes.

saturation

Landslides often occur after heavy __ or rapid snowmelt, destabilizing soil.

rainfall

Striations formed by glaciers can serve as indicators of former __ directions.

ice-flow

The __ may serve as a natural reservoir when landslides occur, blocking stream flow.

dam formed behind landslides

Preventive measures against landslides may include the planting of __ vegetation.

stabilizing

Creep often leaves telltale __ that indicate the occurrence of slow movement.

signs