Earth Science Notes, Questions, and Study Resources

Graph of P & S Wave Travel Times, showing Travel time in minutes across distance in kilometers for P and S waves. S wave starts at zero kilometers, zero minutes, and increases to 10,000 kilometers, 25 minutes. P wave starts at zero kilometers, zero minutes and increases to 10,000 kilometers, 13 minutes. About how far does the S wave travel through Earth in 13 minutes? A. 2,000 km B. 4,000 km C. 6,000 km D. 8,000 km

Earth and Planetary Surface Processes Winter 2017 Problem set 6 Due in class Wed 8 March, 3pm. Office hours 10am-11am, Hinds 467 Monday 6 March (note change in time from 9am). Q1. Plot the expected steady-state pattern (as a function of distance from the crest) of discharge of regolith on a convex hillslope in a climate in which the production rate of regolith is 20 mm/yr. Report your answer in m2/year. If the regolith was 0.8 m thick, what would be the spatial pattern of the mean downslope velocity of the regolith? How would these numbers change if 25% of the mass loss occurred in solution (dissolved in rainwater)? (From Anderson & Anderson) Q2. From Hartley et al., Nature Geoscience, 2011: Seismic reflection profiling between Iceland and the UK shows a drowned landscape that was above sea level 55 Ma. The landscape was cut into mudstones and is now buried beneath >1 km of sediment, plus 700m of water. The landscape (black square in the below figure) was uplifted and then reburied due to the arrival of the head of mantle plume whose “stalk” now fuels volcanism at Iceland: River profiles (gray is data, black is model): What is the slope of the knickpoint marked β? What is the (range of) approximate drainage areas at β? Assuming n=1 in the streampower law (so that knickpoint shape is preserved on retreat), what is the knickpoint retreat rate vAm ? You can assume v = 2.75 Myr-1 and m = 0.5 for this question. Approximately how many years prior to the landscape becoming “drowned” (frozen in shape) was the knickpoint initiated? Refer to Figure 1. Assume the initiation of knickpoint β corresponds to the arrival of the “mushroom head” of the mantle plume, and the drowning of the landscape corresponds to the switch to the modern, narrow “plume tail” configuration. What is the area over which uplift occurred? Assuming the red-circled area was horizontal and below sea level before the plume arrived, what is the volume of uplifted rocks? Assuming the drowned landscape under investigation is representative of the fractional erosion of the uplifted landscape across the whole red-circled area, what is the volume of rocks fluvially eroded in the plume area during the plume event? What is the erosion flux in km3 yr-1? How does this compare to the Holocene pre-dam global sediment flux of 8 km3 yr-1? Q3. In lecture we discussed accumulation of a stable cosmogenic isotope in a rock undergoing exhumation, and we also discussed accumulation of a radioactive cosmogenic isotope in a rock that has no erosion. In this question we will combine exhumation and decay. Assume a production rate of 10Be of 5 atoms/(gram quartz)/yr at the surface, with an e-folding depth of 1 m (so the production rate is 1.84 atoms/(gram quartz)/yr at 1m depth). 10Be decays exponentially with a half-life of 1.4 Myr. Plot the expected concentration of 10Be at the surface, as a function of erosion/exhumation rate, for a quartzite rock. Make sure to consider the endmembers of very slow erosion/exhumation (for which the 10Be concentration will reach equilibrium between production and decay), and the endmember of very fast erosion/exhumation (for which decay is unimportant in setting the 10Be concentration)

why is the s-p interval used to determine the distance of an earthquake

what are seismic waves

"If Earth were the size of a basketball, how big would the Moon be? How far away would it be? A. The Moon would be the size of a grapefruit and would be about 5 feet away. B. The Moon would be about the size of a tennis ball and would be 30 feet away. C. The Moon would be the size of a golf ball and would be about 5 feet away. D. The Moon would be the size of a basketball and would be about 20 feet away."

"Which choice best describes the phosphorus cycle? A. Movement of phosphorus between the atmosphere and land. B. Movement of phosphorus in the atmosphere. C. Movement of phosphorus between land, ocean, and living organisms."

State at least five differences between solstice and equinox.

"Graph of P & S Wave Travel Times, showing Travel time in minutes across distance in kilometers for P and S waves. S wave starts at zero kilometers, zero minutes, and increases to 10,000 kilometers, 25 minutes. P wave starts at zero kilometers, zero minutes and increases to 10,000 kilometers, 13 minutes. About how far does the S wave travel through Earth in 13 minutes? A. 2,000 km B. 4,000 km C. 6,000 km D. 8,000 km"