Landscape

Yellowstone national park is an alpine glacial landscape and the glaciers are responsible for shaping the beautiful scenery and landscape we see today. The park has been through at least 3 major glaciations. The last period, the Pinedale glaciation period ended about 14,000 years ago. Even though the ice has long been melted, the land still bears evidence of its existence. Glaciers result in depositional and erosional forms, both of which are abundant in the park. Depositional forms from the ablation zone are the result of the glacier front retreating. Till is a mixture of gravel, boulders, clay and sand left behind by a glacier. Often till is deposited in ridges known as moraines. 

A terminal moraine near Bannock Peak. From this ridge of till we know the maximum extent of the glacier before it receded.

http://www.nps.gov/features/yell/slidefile/geology/glacial/Inside%20Yellowstone%20Park/Page.htm

 Erosional forms result from the glacier sliding along the landscape. One of the most telling forms of a glacial landscape are parabola valleys. As the glacier slides along the land, it carves out the landscape into a u-shape, as opposed to the v-shape that rivers carve out in fluvial landscapes.

Can you see the u-shape of the valley?

http://www.nps.gov/features/yell/slidefile/geology/glacial/Inside%20Yellowstone%20Park/Page-1.htm

Hanging valleys are a formed when a glacier in a u-shaped valley at a higher elevation feeds into a glacier of larger volume at a lower elevation. A perfect example of this is Bridal Veil Falls. 

The waterfall is flowing from the hanging valley into the other deeper valley. 

http://lurbano-6.memphis.edu/Classes/index.php/Alpine_glacial_features

As the glacier moved it picked up large boulders and rocks and when the glacier melted, it deposited them across the landscape. These scattered boulders are known as erratics.

A large erratic along the road to Inspiration Point. This particular boulder was carried here 15 miles by the glacier.

http://travellogs.us/Miscellaneous/Geology/Glacial%20erratics/Glacial%20Erratic.htm

http://lurbano-6.memphis.edu/Classes/index.php/Alpine_glacial_features

http://www.geocaching.com/seek/cache_details.aspx?guid=8be93682-6e8c-4cf7-97b4-af94f5d678d8

http://travellogs.us/Miscellaneous/Geology/Glacial%20erratics/Glacial%20Erratic.htm

http://www.nps.gov/archive/yell/insideyellowstone/0043general.htm

Casey Allen class lectures

Climate and Weather

Yellowstone National Park is located primarily in the north east corner of Wyoming but it extends into parts of Idaho and Montana. The mountain ranges and changes in altitude contribute to the climate, which is why the climate encompasses Semiarid (Midlatitude) Steppe climate (BSK) and Highland climate (H).

http://printable-maps.blogspot.com/2008/09/climate-maps-united-states-and-canada.html


Insulation, angle of incidence, global wind patters, air masses and altitude all affect climate, the primary factor in temperature and precipitation of a region. The parks' summer diurnal temperatures are pretty variable and range from highs in the 70s/80s to lows below freezing, especially at higher altitudes. Winters are very cold and the highs/lows stay from below zero to about 20 degrees most of the winter. Precipitation is also variable and ranges from 15 inches annually to 80 inches in the southwestern part of the park.

The climate of Yellowstone is similar to that of Denver, hot and dry summers and wet winters. Yellowstone has colder winters though and more severe temperature swings than Denver. 
http://www.wrcc.dri.edu/pcpn/us_precip.gif

One form of precipitation is convection, which is a major cause of weather phenomenon like thunderstorms. Weather has vast impact on humans; floods, lightning and tornadoes are among the leading causes of weather fatalities. Tornadoes in Yellowstone are rare, but on July 21, 1987, the highest altitude tornado ever recorded in the US raged up and down the mountains in the park.

The F4 left a 24-mile long, 1.5-mile wide path of destruction, uprooting up to 1,000,000 trees over 15,000 acres. Wind speeds were estimated at between 207 and 260 miles per hour.
http://www.qwiki.com/q/#!/Tornado_Alley


http://en.wikipedia.org/wiki/Yellowstone_National_Park#Climate
http://en.wikipedia.org/wiki/Teton%E2%80%93Yellowstone_tornado
http://www.yellowstone-natl-park.com/weather.htm