Lab 7 - Erosion & Deposition

GEOG 1800 Physical Geography Lab Lab #7 - Erosion & Deposition General Instructions: Read the assignment and exercise instructions carefully. Type your answers directly into the spaces/tables provided. Save your document with a new file name (e.g. “ YourName _Lab7_GEOG1800”) and upload it to the Canvas Assignment page. Key Terms & Concepts: ● Drainage ● Meanders ● Point bar ● Cut bank ● Delta ● Floodplains ● Glaciers ● Glacial retreat ● Sea level change Objectives: ● Investigate the formation of drainage systems and channel erosional and depositional features. ● Construct a hypothesis and analyze data about the changing size of glaciers over time. ● Study linear trend plots of sea level to construct a hypothesis about mean sea level (MSL) change. Exercise 1: Fluvial Erosion & Deposition [WATCH] Stream Table Demo (1:50) and answer the following questions: 1. What process was demonstrated when the food coloring was added to the streamflow? ANSWER : 2. Outside of meander/inside of meander, which house will fall in? Why? ANSWER : 3. Would you expect meanders to widen or become more narrow through the life of the stream? Why? ANSWER: 4. How does the river delta form in the stream table? ANSWER: Exercise 2: Floodplains Management [WATCH] What is Floodplains by Design? (6:00) and answer the following questions: 5. What are the 4 benefits of “natural” floodplains? (HINT: start at 0:50) ANSWER: 6. Compare and contrast the two flooding scenarios described in the video (at 1:58 & at 4:22). Specifically, describe the basic flooding “timeline” and what the impacts of the human-made alterations have on the surrounding areas in both scenarios. 1

ANSWER: Exercise 3: Glacial Loss Part A: Assume you work for the Northern Rocky Mountain Science Center. Your job is to determine the extent of glacier recession within Glacier National Park as part of a study examining the effects of climate change. You access photographic data of 20 glaciers from 1966 and compare their area to photographs of the same glaciers taken in 2005. Based on this quick look, you make a hypothesis that the glaciers have lost 15% of their area . Process the data in the table below by calculating the total area of the 20 selected glaciers for 1966 and 2005. Glacier Name 1966 Area (m²) 2005 Area (m²) Agassiz 1,589,174 1,039,077 Ahern 589,053 511,824 Blackfoot 2,334,983 1,787,640 Carter 273,834 202,696 Chaney 535,604 379,688 Grinnell 1,020,009 615,454 Harrison 2,073,099 1,888,919 Ipasha 321,745 212,030 Kintla 1,728,828 1,136,551 Logan 503,298 302,146 Old Sun 421,254 370,257 Piegan 280,107 250,728 Pumpelly 1,489,137 1,257,211 Rainbow 1,284,070 1,164,060 Salamander 225,621 172,916 Sexton 400,444 276,780 Sperry 1,339,244 874,229 Swiftcurrent 261,410 223,519 Thunderbird 358,284 238,331 Two Ocean 428,828 275,022 2

ANSWER: Part B: Table 3.1 presents 20 years of sea level change from NASA’s Jason-2/OSTM Mission. Remember that sea level change is relative to the average height of Earth’s ocean over the entire time period . Global Sea Level Change (mm/year) data is relative to the average over the entire time period January 1993 -15.89 January 1994 -8.26 January 1995 -6.81 January 1996 -7.81 January 1997 -5.02 January 1998 5.70 January 1999 6.46 January 2000 12.11 January 2001 14.12 January 2002 19.25 January 2003 23.65 January 2004 25.45 January 2005 29.09 January 2006 31.66 January 2007 32.55 4

January 2008 32.76 January 2009 36.45 January 2010 42.33 January 2011 36.85 January 2012 45.98 TABLE 3.1 12.Based on the data presented in Table 3.1, is your hypothesis supported or not supported by the data? Explain your answer. ANSWER: 5