- Title Information
- Title
- Holocene climate evolution of the eastern tropical Pacific told from high resolution climate records from the Peru margin and equatorial upwelling regions
- Name:
Personal
- Name Part
- Chazen, Caitlin R
- Role
- Role Term:
Text
- creator
- Origin Information
- Copyright Date
- 2011
- Physical Description
- Extent
- xix, 252 p.
- digitalOrigin
- born digital
- Note
- Thesis (Ph.D. -- Brown University (2011)
- Name:
Personal
- Name Part
- Herbert, Timothy
- Role
- Role Term:
Text
- Director
- Name:
Personal
- Name Part
- Tullis, Jan
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Russell, James
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Altabet, Mark
- Role
- Role Term:
Text
- Reader
- Name:
Personal
- Name Part
- Koutavas, Athanasios
- Role
- Role Term:
Text
- Reader
- Name:
Corporate
- Name Part
- Brown University. Geological Sciences
- Role
- Role Term:
Text
- sponsor
- Genre (aat)
- theses
- Abstract
- The Peru margin plays a significant role in global climate dynamics and biogeochemical cycling. Situated between 4-15°S off the western coast of South America the Peru upwelling region fuels one of the world's most productive marine ecosystems. This high surface productivity along with poorly ventilated source waters places the Peru margin within the world's three oxygen minimum/denitrification zones. These denitrification regions represent the major loss of nitrate (an important macronutrient) from the ocean system. As a consequence of this, long-term changes in the strength and/or size of the Peru margin upwelling system have a fundamental impact on the world's carbon cycle. The Peru coastal current merges with equatorial upwelling to form the eastern equatorial cold tongue. Instability of the tropical cold tongue drives the coupled oceanic- atmospheric El Niño Southern Oscillation (ENSO). This coupled mode has been described as a 'globalizer' for its ability to drive global climate on both millennial and orbital timescales. Despite the significance of the Peru margin, little is known about how the climate evolved during the recent past. The work presented in this dissertation focuses on understanding how the Peru margin climate has evolved since the end of the Last Glacial Maximum, and identifying what the driving mechanisms of those climate changes were. Here we reconstruct the key environmental parameters of the Peru margin climate:Sea surface temperature (UK'37 index), phytoplankton productivity (Alkenone-C37total and biogenic silica and subsurface ventilation (δ15N of bulk organics). Our results suggest that the remote ventilation of the Peru thermocline dominated over the oxygen demand imposed by local productivity during the early Holocene. Near the middle Holocene a dramatic increase in climate variability was accompanied by a shift toward more locally driven climate dynamics, revealed through the relationship between our surface and subsurface climate proxies. The late Holocene section of our record oscillates between centennial-scale periods of locally driven and non-locally driven subsurface ventilation. We therefore argue that the strength of the Peru oxygen minimum zone reflects a balance between high and low latitude climate forcings.
- Subject
- Topic
- Peru margin
- Subject
- Topic
- El Nino Southern Oscillation
- Subject
- Topic
- Climate Variability
- Subject
- Topic
- Holocene
- Subject
- Topic
- OMZ
- Subject (FAST)
(authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1353233")
- Topic
- Holocene Geologic Period
- Record Information
- Record Content Source (marcorg)
- RPB
- Record Creation Date
(encoding="iso8601")
- 20111003
- Language
- Language Term:
Code (ISO639-2B)
- eng
- Language Term:
Text
- English
- Identifier:
DOI
- 10.7301/Z0D50K7P
- Access Condition:
rights statement
(href="http://rightsstatements.org/vocab/InC/1.0/")
- In Copyright
- Access Condition:
restriction on access
- Collection is open for research.
- Type of Resource (primo)
- dissertations