News Release

This week from AGU: Q&A with Rex Buchanan, solar storm satellite, pollution from aquifers

Peer-Reviewed Publication

American Geophysical Union

From AGU's blogs: Q&A with journalist-turned-geologist Rex Buchanan

After decades as a science reporter, interim director of the Kansas Geological Survey (KGS) Rex Buchanan now finds himself at the epicenter of a media frenzy. Read parts one and two of a three-part series featuring an interview between Buchanan and University of California, Santa Cruz, science journalism student, Kerry Klein, in The Plainspoken Scientist.

From Eos.org: Changing of the Guard: Satellite Will Warn Earth of Solar Storms

This summer, Earth gets a new guardian--the Deep Space Climate Observatory--to help warn astronauts and operators of critical planetary infrastructure about the Sun's raging magnetic storms.

From AGU's journals: Underground Aquifers Spew More Pollution Into Oceans Than Rivers

When it comes to oceanic pollution, underground seepage from coastal aquifers trumps runoff from rivers, a new study says. Coastal aquifers are pockets of permeable earth - gravel, sand or silt -- that trap water. Much like rivers, these reservoirs absorb ground contaminants, such as fertilizer, subterranean carbon and metals. These chemicals can subsequently leak from the seabed into the ocean, through a process known as submarine groundwater discharge (SGD), but the scale of this seepage remains in question.

Kwon et al. created a mathematical model to estimate SGD of radium-228, a radioactive isotope that serves as readout for terrestrial leaching. Prior models made indirect estimates of SGD by subtracting the recorded levels of radium-228 deposited by rivers, dust blown from land, and diffusive fluxes from coastal sediments from the steady-state of radium-228 found in marine water. This earlier method is more accurate near shore, according to the authors, but becomes problematic for open seas, where accurate recordings at depth are sparse.

To circumvent this issue, the team posits a new model to get accurate recordings at depth based off tactics used to estimate the global mixing of ocean acidification. When combined with radium-228 data, this circulation model inferred SGD for the global ocean, excluding the polar seas due to insufficient available recordings of isotope.

They estimate that SGD from coastal aquifers contributes three to four times more terrestrial contaminants to the ocean than river water. Also, the bulk - 70 percent -- of SGD occurs in the Indo-Pacific Oceans, suggesting these regions are more susceptible to natural and man-made pollutants that are stored in coastal aquifers. The findings may also inform future research and policy decisions with regard to biogeochemical changes, pollution cycles and ecosystem dynamics.

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