Record Details
Eddy correlation benthic O₂ exchange rates and characterizations of sediment properties from the central Oregon shelf at 30 meters
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Eddy correlation benthic O₂ exchange rates and characterizations of sediment properties from the central Oregon shelf at 30 meters |
| Names |
McCann-Grosvenor, Kristina
(creator) Reimers, Clare E. (advisor) |
| Date Issued | 2011-01-24 (iso8601) |
| Note | Graduation date: 2011 |
| Abstract | Rates of benthic O₂ exchange are important measurements for determining organic matter remineralization, and can shed light on factors driving biogeochemical processes in coastal environments. Measurement of in situ O₂ consumption and production within permeable sediments, such as those found over ~43% of the Oregon-Washington shelf, has traditionally been done using methods that underestimate the flux for environments affected by waves. Modified from atmospheric research, the non-invasive eddy correlation technique can measure O₂ flux across the sediment-water interface without disturbing the natural hydrodynamic flow. In 2009, eddy correlation measurements were made at discrete times over a 7-month period at a 30 m site off Yaquina Head, Newport, OR. The results of this newly developed method are evaluated here, together with properties of sediment cores taken at the study site. O₂ flux was found to be primarily into the bed (-6.2 to -30.7 mmol m⁻² d⁻¹) and was enhanced during periods of higher bottom water O2 concentration. Contributions to O₂ flux were seen in eddy correlation cospectra at surface wave frequencies and dependent on wave height. The sediments were fine sands with permeabilities of 1.3-4.7 x 10⁻¹¹ m². Sediment pigment and organic carbon concentrations were low (chlorophyll-α : 0.03-0.45 μg g⁻¹, phaeophytin-α: 0.6-1.4 μg g-1 and organic carbon: 0.07-0.11 wt %), indicating high rates of organic matter export and/or remineralization. From these results it is inferred that physical forcing and changes in bottom water properties affect the inner shelf sedimentary environment more than seasonal cycles in primary production. |
| Genre | Thesis/Dissertation |
| Topic | oxygen exchange |
| Identifier | http://hdl.handle.net/1957/19918 |
