Question 1
A geologist is looking at deposits along a river below a large volcano. She finds large boulders mixed with sand and mud, and all of the material is comprised of volcanic rocks, particularly the mud which is volcanic ash. She quickly realizes these deposits represent an ancient ________.
◦ earthflow
◦ slump
◦ rock avalanche
◦ lahar
Question 2
In deserts of southwestern North America developers often build houses in dry stream beds and build only minimal subsurface drainage systems to handle a flow of water comparable to the size of the dry stream channel. Is this a reasonable development model in the interest of public safety?
◦ No, giant rock avalanches could come down the valley covering houses.
◦ Yes, any potential flooding catastrophe would be a 100 year flood event and would have adequate warning to evacuate people for safety, so the drainage system is adequate.
◦ Yes, although flash floods can occur, using the channel size is a reasonable estimate of the maximum flood size.
◦ No, flash floods can produce high viscosity mudflows that would not be captured by the drainage system and could flow out over the valley, destroying everything in its path.
North Pacific right whale
A Stream Hydrograph
Chinese workers on a railway in the far West. “Without them,” Leland Stanford, president of the Cent
A sod house in North Dakota, 1896. Individual “bricks” of sod were hewn from the ground and stacked
A partial stream sampling exhaust probe being used to measure exhaust gases in parts per million ...
north of east, east of north, east of south, south of east, etc.