What is a glacier? A thick mass of ice accumulated over a long period of time, that is able to flow.
Continental Glacier • Found only in Greenland & Antarctica • Massive ice sheets that radiate out from one or more centers. • Continental Glaciers covered Gondwana 300 mya. • Continental Glaciers covered North America & Eurasia <15,000 years ago. ( The Nebraskan, Kansan, Illinoian, and Wisconsin Glacial Periods) • Extremely valuable in climatology, vital to planet’s environmental well-being.
Valley Glaciers • Much smaller in scale, but still very impressive. • Found in all high mountainous areas, even on equator (Andes. Mt. Kenya and Kilimanjaro) • Despite their name, actually start on mountain peaks during periods of long winters and short, cool summers. • Over time, the accumulated snow turns to firn, which begins to flow downhill. • Glaciers act as gargantuan bulldozers, plowing up everything in their path (glacial plucking). • Glaciers are important shapers of landforms both when they advance (Fig. 5.4, p.126), and when they retreat(Fig. 5.7, p. 128). • Important indicator of climate change!
When Glaciers come, When Glaciers go… Fig. 5.7, p. 128
Terms you DON’T want to MELT away … Kettle Drumlin Esker Kame Firn Iceberg Glacial plucking Glacial striations Glacial trough Hanging Valley Cirque Arete Glacial Horn Fjord Glacial Till Glacial Erratic Moraines Outwash Plain
More “Cool” Pics! http://www.uwgb.edu/dutchs/EarthSC202Slides/glacslid.htm http://www.semi.sd36.bc.ca/mleziva/unit5/U05L01.htm
GLACIERS in TEXAS??? NEVER!!!!!!!!!!!!! BUT – They DID effect our climate! Texas during the Pleistocene Ice Ages was Cooler & Drier!
Can we still find the Ice Ages in Texas? Of Course!
PLEISTOCENE FOSSIL LOCALITIES 1 = Nueces River 2 = Ingleside 3 = Aransas River 4 = Bee County 5 = Petronila Creek • GLACIAL RELICS • Bastrop State Park • Lost Maples State Natural Area • McKittrick Canyon in Guadalupe Mtns National Park