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1. 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

2. The lesser Himalayas are the mid-section of the Himalayas Shown in reddish colors on the map below: http://en.wikipedia.org/wiki/Geology_of_Nepal

3. Area of investigation: The Indus Water Shed The Indus Delta http://www.pnas.org/content/107/12/5317/F1.large.jpg

4. Area of investigation: http://www.lib.utexas.edu/maps/middle_east_and_asia/india.gif

5. 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/

6. Steep slopes Tectonic converging plates push land masses together breaking lithosphere into blocks causing thrust fault mountains Gravity Pulls downward on mountain slopes causing it to become harder to build mountain Taller mountain = greater gravitational forces (friction) Friction Blocks sliding over one another create friction wearing or breakdown of material http://www.geo.arizona.edu/Antevs/ecol438/crust_05.gif

7. 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 http://www.geo.fu-berlin.de/fb/e-learning/geolearning/en/mountain_building/weathering/Erosion3/index.html

8. Glacial movement New snow accumulates causing ice to flow down slope, friction grows between ice and rock, rock is destroyed and carried by the riverdown slope http://www.geo.umass.edu/structure/analog_models/Erosion_MountBuilding.pdf

9. Geologists believe the uplift of the Tibetan Plateau (23 to 10 million years ago)intensified the monsoon climate for the Himalayas http://asaa.asn.au/publications/ac/2008/asian-currents-08-06.html Topography plays an integral part in rainfall along mountainous regions. This is enhanced during monsoon seasons.

10. Rain and Lack Of… Monsoons and Erosional processes: Oct – Feb Winter 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. http://en.wikipedia.org/wiki/File:India_climatic_zone_map_en.svg

11. 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://web.mst.edu/~rogersda/umrcourses/ge301/what%20is%20a%20100%20year%20flood.htm

12. 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://readerfeedback.labs.wikimedia.org/wiki/File:India_southwest_summer_monsoon_onset_map_en.svg http://www.geog.ucsb.edu/~bodo/pdf/bookhagen05_amy_nw_himalaya.pdf

13. 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