Upload
triage
View
43
Download
1
Tags:
Embed Size (px)
DESCRIPTION
Climatic Controls of Holocene Erosion of The Lesser Himalayas. http://www.diycalculator.com/imgs/cvision-timeline-03.gif. http://media.eurekalert.org/release_graphics/Geo_1.jpg. The lesser Himalayas are the mid-section of the Himalayas Shown in reddish colors on the map below:. - PowerPoint PPT Presentation
Citation preview
http://www.diycalculator.com/imgs/cvision-timeline-03.gif
Climatic Controls of
Holocene Erosion of
The Lesser Himalayas
http://media.eurekalert.org/release_graphics/Geo_1.jpg
http://en.wikipedia.org/wiki/Geology_of_Nepal
The lesser Himalayas are the mid-section of the HimalayasShown in reddish colors on the map below:
http://www.pnas.org/content/107/12/5317/F1.large.jpg
Area of investigation: The Indus Water Shed The Indus Delta
http://www.lib.utexas.edu/maps/middle_east_and_asia/india.gif
Area of investigation:
Factors that control the rate of erosion in the Indus Delta Area:
• Steep slopes• Tectonic plate
movement• Sparse
vegetation• Water –
Glaciation and High rain fall
• Monsoons
http://hunzatimes.wordpress.com/northern-areas-photo-gallery/indus_river_from_karakouram_highway1/
Steep slopes Tectonic converging plates push land masses
together breaking lithosphere into blocks causing thrust fault mountains
GravityPulls downward on mountain slopes causing it to
become harder to build mountainTaller mountain = greater gravitational forces (friction)
FrictionBlocks sliding over one another create friction wearing
or breakdown of material
http://www.geo.arizona.edu/Antevs/ecol438/crust_05.gif
http://www.geo.fu-berlin.de/fb/e-learning/geolearning/en/mountain_building/weathering/Erosion3/index.html
Water (solid or liquid)Always runs toward base level
creating friction (erosion) Tectonic uplift causes river
bottom to rise adding energy to the system
http://www.geo.umass.edu/structure/analog_models/Erosion_MountBuilding.pdf
Glacial movementNew snow accumulates causing ice to flow down slope, friction grows between ice and rock, rock is
destroyed and carried by the river down slope
http://www.geo.umass.edu/structure/analog_models/Erosion_MountBuilding.pdf
Geologists believe the uplift of the Tibetan Plateau (23 to 10 million years ago) intensified the monsoon
climate for the Himalayas
Topography plays an integral part in rainfall along mountainous regions. This is enhanced during monsoon seasons.
http://asaa.asn.au/publications/ac/2008/asian-currents-08-06.html
http://en.wikipedia.org/wiki/File:India_climatic_zone_map_en.svg
Monsoons and Erosional processes:
Oct – FebWinter sun retreats South. The land mass cools rapidly air pressure builds over the North causing cold air to descend and sweep down from the Himalayas. Dry winds blowing from the Northeast creating arid conditions. Giving way to desert, dry shrub and sparse vegetation.
Rain and Lack Of…
http://web.mst.edu/~rogersda/umrcourses/ge301/what%20is%20a%20100%20year%20flood.htm
June – Sept.Moist wind blows in from the Southwest. The Himalaya Mountains act as a high wall blocking wind from passing into central Asia. Warm moist air rises causing a drop in temperature causing monsoon storms and precipitation.
http://readerfeedback.labs.wikimedia.org/wiki/File:India_southwest_summer_monsoon_onset_map_en.svg
Monsoon Season:When rain migrates far into the mountains and reaches regions shielded by orographic barriers large winds and huge amounts of precipitation on arid desert landscape increases debris flows and erosional hill slope processes increasing sediment evacuation.
The largest erosional feature
for the lesser Himalayas
http://www.geog.ucsb.edu/~bodo/pdf/bookhagen05_amy_nw_himalaya.pdf
Recall: Water Runs Down Slope carrying large amounts of sediment with it.
In this case into the Indus River Delta
http://www.geo.umass.edu/structure/analog_models/Erosion_MountBuilding.pdf