Question

the deepwater horizon oil spill of 2010 had devastating effects on ecosystems in the gulf of mexico at the time it happened. a new study by giovanna mcclenachan and r. eugene turner suggests that the negative effects of the spill are still ongoing ten years later, especially as they relate to shoreline loss. in particular, mcclenachan and turner found that there was a 50% loss of soil strength in coastal louisiana wetlands, which, eight years on, had failed to recover. which finding from mcclenachan and turners research, if true, would most directly support their claim about soil strength? a ten years on, marsh soils still showed higher traces of oil than they did before the spill, but less than they had at their peak in 2012. b marsh sites with more exposure to oil eroded first, but their erosion caused neighboring sites with less oil contact to erode as well. c oil causes the bottom layers of the shoreline edge to erode faster; the weight of the overhanging shore then speeds up erosion in turn. d soil strength, measured in kilopascals, went from about 40 kpa in 2010 to 20 kpa in 2020 in the top soil layer.

Explanation:

The claim is about soil - strength loss due to the oil spill. Option D directly shows a decrease in soil strength (from 40 kPa in 2010 to 20 kPa in 2020 in the top soil layer), which supports the claim. Option A is about oil traces, Option B is about erosion's spread, and Option C is about the mechanism of shoreline erosion, none of which directly support the soil - strength claim.

Answer:

D. Soil strength, measured in kilopascals, went from about 40 kPa in 2010 to 20 kPa in 2020 in the top soil layer