Lab 6: Remote Imaging Flashcards
remote sensing
the science of obtaining information about objects or areas from a distance, typically from aircraft of satellites.
passive remote sensing + example
record natural energy that is reflected or emitted from the Earth
satellite images
active remote sensing + example
use internal stimuli to collect data
a laser beam projects a laser into the Earth and measures the time it takes to reflect back
alluvial deposits examples
meandering rivers
braided rivers
meandering river
the flow is in a single continuous winding channel
braided river
the flow is divided into many channels across a wide flood plane
point bar
inside of a meandering river’s meander
meander scar/cut-off
the point in the meander that cuts off to form an oxbow lake
scrolls
surface of point bars appearing as feather edges that point downstream
alluvial fan cause
caused by a sudden decrease in slope
distributary channels
near where the river enters standing water, levees form and bind the banks of the river. They are deposited during floods
aeolian deposits example in Alberta
sand dunes
longitudinal dune
a sand dune that forms under conditions of high wind speeds in areas of small sand supply (looks like ripples)
barchans
formed in a similar way to longitudinal dunes but with greater sand supply.
Arched hill with a convex side to the wind direction
parabolic dunes
more vegetation and decreased wind velocities
arched hill with concave to the wind direction
how we recognize landslides on satellite photos
- hummocky surface,
- sag ponds,
- light toned areas called scarps,
- obstruction and diversion of drainage,
- abrupt changes in vegetation
sag pond
undrained depression within the displaced material
fall
starts with the detachment of soil or rock from a steep slope along a surface on which little or no shear displacement takes place
topple
the forward rotation, out of slope, of a mass of soil or rock.
slide + 2 types
the downslope movement of a soil or rock mass occurring by shear displacement
translational slide
rotational slide
translational slide
planar surface of failure - indicates bedrock
rotational slide + other name
(also called slump)
curved surface of failure, concave upwards
spread
spreading of material at a very small angle`
flow example
sand flows through a crack
the displaced mass exhibits continuous internal deformation
avalanche + how can we recognize
snow and ice + debris
coarse gravel and boulders are deposited in fans and tongues at the base of slopes
what kind of valley do glaciers from
u shape valleys
hanging valleys
tirbutary valleys enter over a steep rock-face
cirques
deep excavated hollows in mountains from glaciers
till
an unsorted and unstratified sediment deposited directly from ice consisting of everything from clay to boulders
stratified drift
deposited from the meltwater draining from the glacier
what are 2 glacier deposits
till,
stratified drift
moraines
landforms built up from till
drumlin
pointy end points in the direction that the glaciers travel
flutings
very elongated drumlins
eskers
deposits of stream flowing under the ice of in ice walled channels
long thin walls of till (look like veins on a weiner)
kames
alluvial cones that build up at the base of glacial streams falling from the glacier surface
outwash fan/plain
sediment carried away is deposited in more gentle sloping fans in front of the glaciers
kettle
ice falls of the glacier and creates an indent in the ground, then melts creating a pocket of water
why are eskers, kames, and some outwash deposits important
since heavier sediment drops first, they can be a valuable source of gravel and valuable minerals
How to tell which way a river flows
look at individual meanders. If you split the meander down the middle, water flows from the side that is shorter to the side that is longer
reflection seismology formula
t = 2 (d/V)
t is directly read from the graph (the time is the time it takes to go there and back)
ground penetrating radar signifigance
buried objects appear as hyperbolic shapes
how to recognize a scarp
light coloured line that seperates a non landslide area from a landslide area (hummocky, sag ponds)
along a meandering river where does mass movement occur
along the scarp, it is only caused by the movement/erosion of ground by the river.
how to recognize rotational slide
a curved surface of failure (scarp)
how to recognize a translational slide
a straight surface of failure (scarp)
