Planktic foraminifers of the California Current at 42°N : last glacial maximum and present Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/9k41zj15s

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • MOCNESS plankton tows, sediment traps and sedimentary material are used to determine the linkage between bio-physical forcing and foraminiferal response over a range of time scales from the event scale to the glacial interglacial cycle. The annually averaged planktic foraminiferal fauna of the modem California Current is a diverse community composed of individuals from subarctic, transitional, and subtropical foraminiferal assemblages. This community is more diverse, but less abundant in total standing stock and shell flux than the subarctic community of the Gulf of Alaska. The use of plankton tow and isotopic data allow us to partition the foraminiferal community into shallow dwelling euphotic zone species and deep dwelling sub-thermocline species. On both the event and seasonal time scales, heterotrophic species were most abundant in cold, biomass rich coastal waters. In contrast, species which harbored endosymbionts were more abundant in oligotrophic waters with higher ambient light levels. During the Last Glacial Maximum (LGM), the diverse modern fauna was replaced with a low diversity, high flux, heterotrophic community similar to that of the modern Gulf of Alaska. Modern analog temperature estimates suggest the California Current was roughly 3°C cooler during the LGM than today. Coupled with oxygen isotopic results from G. bulloides, the surface thermal structure implies an equatorward flowing glacial California Current at these sites. The Polar Front thus remained north of these locations during the LGM. Comparison of glacial G. bulloides carbon isotopes and shell accumulation rates with organic carbon flux estimates implies the glacial California Current was (1) higher in nutrient content, (2) lower in plankton biomass, and (3) lower in export carbon flux than its modem counterpart. This description suggests that during the LGM the plankton community of the California Current was very similar to the modern plankton community of the Gulf of Alaska.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 256 Grayscale) using Capture Perfect 3.0.82 on a Canon DR-9080C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Made available in DSpace on 2011-09-23T19:49:40Z (GMT). No. of bitstreams: 1 OrtizJosephD1996.pdf: 4688919 bytes, checksum: a2c88c6332439c9904710bdcb585fab3 (MD5) Previous issue date: 1995-05-02
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2011-09-23T19:28:53Z (GMT) No. of bitstreams: 1 OrtizJosephD1996.pdf: 4688919 bytes, checksum: a2c88c6332439c9904710bdcb585fab3 (MD5)
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2011-09-23T19:49:40Z (GMT) No. of bitstreams: 1 OrtizJosephD1996.pdf: 4688919 bytes, checksum: a2c88c6332439c9904710bdcb585fab3 (MD5)
  • description.provenance : Submitted by Eric Vanderwall (ewscanner@gmail.com) on 2011-09-22T20:24:32Z No. of bitstreams: 1 OrtizJosephD1996.pdf: 4688919 bytes, checksum: a2c88c6332439c9904710bdcb585fab3 (MD5)

Relationships

In Administrative Set:
Last modified: 08/19/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items