Carol Pride - Academia.edu (original) (raw)

Papers by Carol Pride

Journal of Plankton Research, 1996

Distinct increases in plankton productivity occur annually in the Gulf of California and are rela... more Distinct increases in plankton productivity occur annually in the Gulf of California and are related, at least in part, to wind-driven changes in upper-ocean conditions. In particular, a rapid increase in plankton shell fluxes occurs in late fall (November), and is associated with a shift to northerly winds and cooling of surface temperatures that induce mixing of the upper ocean. The observed succession in the phytoplankton is attributed to this destabilization of surface waters and may reflect the ability of different groups to respond to varying surface water nutrient levels. The unraveling of such relationships between plankton production and hydrographic conditions is critical to improving our ability to reconstruct quantitatively past climates.

AGU Fall Meeting Abstracts, Dec 1, 2004

Phytoplankton monitoring is being used at Savannah State University to provide research experienc... more Phytoplankton monitoring is being used at Savannah State University to provide research experience for all upper-level marine science majors, to provide in-depth senior research projects, to engage lower-level students in marine science activities beyond the classroom, and to collect baseline data for faculty research proposals. The framework is built around a commitment to maintain a tidal creek monitoring site for larger phytoplankton (diatoms and dinoflagellates >20 microns) as part of the Southeast Phytoplankton Monitoring Network (SEPMN). Field supplies and on-going training are supported by SEPMN. Marine science majors monitor a series of Wilmington River estuary sites as part of a group research project in an upper-level course offered each spring. The group research assignment includes the writing of a full research report with citations from the primary literature and peer review of drafts. A few students are encouraged to pursue their senior research project in this field and maintain sampling over the remainder of the year. They have freedom to design their own project in the broader context of eutrophication, high frequency temporal variability, seasonality, drought/flood cycles, comparisons between estuaries of differing river discharge or extension of sampling offshore. Senior researchers help to train freshmen/sophomore field assistants to insure consistency in the monitoring from one year to the next. Student data from the Wilmington River estuary cover the greatest portion of an annual cycle. Diatoms far outnumbered dinoflagellates at all estuarine sampling locations under both winter and summer conditions. There is a seasonal transition in this estuary from dominance of Asterionella sp. in February to Chaetoceros sp. in June. Chaetoceros sp. were also dominant in the lower Savannah River estuary in June. Dominance of diatoms in these estuaries rather than dinoflagellates is a sign of a relatively healthy ecosystem. These diatoms, however, did include at least one genus associated with eutrophication when present in high cell densities, Pseudo-nitzschia. Pseudo-nitzschia sp. were present in both winter and summer months in the Wilmington River estuary but were only observed to be dominant (41 %) at the most seaward site in late July.

Quaternary Science Reviews, Sep 1, 2004

Sediments deposited on the slopes of the Guaymas and Carmen Basins in the central Gulf of Califor... more Sediments deposited on the slopes of the Guaymas and Carmen Basins in the central Gulf of California were recovered in two box cores. Q-mode factor analyses identified detrital-clastic, carbonate, and redox associations in the elemental composition of these sediments. The detrital-clastic fraction appears to contain two source components, a more mafic component presumably derived from the Sierra Madre Occidental along the west coast of Mexico, and a more felsic component most likely derived from sedimentary rocks (mostly sandstones) of the Colorado Plateau and delivered by the Colorado River. The sediments also contain significant siliceous biogenic components and minor calcareous biogenic components, but those components were not quantified in this study. Redox associations were identified in both cores based on relatively high concentrations of molybdenum, which is indicative of deposition under conditions of sulfate reduction. Decreases in concentrations of molybdenum in younger sediments suggest that the bottom waters of the Gulf have became more oxygenated over the last 100 years. Many geochemical components in both box cores exhibit distinct cyclicity with periodicities of 10-20 years. The most striking are 20-year cycles in the more mafic components (e.g., titanium), particularly in sediments deposited during the 19th century. In that century, the titanium cycles are in very good agreement with warm phases of the Pacific Decadal Oscillation, implying that at times of greater influx of titanium-rich volcanic debris, there were more El Nin˜os and higher winter precipitation. The cycles are interpreted as due to greater and lesser riverine influx of volcanic rock debris from the Sierra Madre. There is also spectral evidence for periodicities of 4-8 and 8-16 years, suggesting that the delivery of detrital-clastic material is responding to some multiannual (ENSO?) forcing.

AAPG Bulletin, 1996

The Gulf of California is an ideal site to study the controls on sedimentary organic carbon (OC) ... more The Gulf of California is an ideal site to study the controls on sedimentary organic carbon (OC) accumulation and preservation. A 5-year sediment trap record provides an estimate of export production in the Gulf. Low C/N ratios (7.3) and heavy [delta][sup 13]C[sub org] values (-20.5[per thousand]) of trapped OC show that it is predominantly of marine origin. Surface productivity is

Geology, Apr 1, 1994

The Gulf of California, though small in size, plays an important role in the global silica cycle.... more The Gulf of California, though small in size, plays an important role in the global silica cycle. The seasonal pattern of biogenic silica flux in the gulf is closely related to that of phytoplankton biomass levels and is controlled by changes in weather and hydrographic conditions. The highest opal fluxes ([approximately] 0.35 g[center dot]m[sup [minus]2][center dot]d[sup [minus]1]) occur during winter

Journal of geoscience education, Dec 1, 2007

A model deployed at Savannah State University (SSU) for enhancing diversity in the geosciences pr... more A model deployed at Savannah State University (SSU) for enhancing diversity in the geosciences provides much needed African-American role models in the sciences for school aged children in the surrounding community. The most common and effective means of getting children excited about nature and science is to immerse them in the natural environment. Our aim is to inspire more young Americans to continue in the geosciences by increasing the number of African Americans teaching in informal educational centers and increasing the number of trained geoscientists teaching in the schools. This program model depends on strong partnership between a university and science educators from formal and informal education settings. In two iterations, this program trained 19 science majors from a historically black university in natural history interpretation and provided outdoor marine science camp experiences to children of a barrier island community. It also provided classroom teaching experience to more than 30 marine science majors who delivered geoscience lessons to nearly 300 school children in one academic year. Twelve percent more marine science graduates have pursued teaching positions in the past two years compared to our long term average.

Paleoceanography, Jun 1, 1999

High‐resolution records of the nitrogen isotopic composition of organic matter (δ15Norg), opal co... more High‐resolution records of the nitrogen isotopic composition of organic matter (δ15Norg), opal content, and opal accumulation rates from the central Gulf of California reveal large and abrupt variations during deglaciation and gradual Holocene changes coincident with climatic changes recorded in the North Atlantic. Homogenous sediments with relatively low δ15Norg values and low opal content were deposited at the end of the last glacial period, during the Younger‐Dryas event, and during the middle to late Holocene. In contrast, laminated sediments deposited in the two deglacial stages are characterized by very high δ15Norg values (>14‰) and opal accumulation rates (29–41 mg cm−2 yr−1). Abrupt shifts in δ15Norg were driven by widespread changes in the extent of suboxic subsurface waters supporting denitrification and were amplified in the central gulf record due to variations in upwelling, vertical mixing, and/or the latitudinal position of the Intertropical Convergence Zone.

Paleoceanography and paleoclimatology, Mar 1, 2020

This special issue of Paleoceanography and Paleoclimatology is dedicated to Dr. Robert C. Thunell... more This special issue of Paleoceanography and Paleoclimatology is dedicated to Dr. Robert C. Thunell for his many contributions to the fields of marine geology, micropaleontology, chemical oceanography, and climate system science. Bob was a highly respected researcher and educator whose commitment to service impacted many throughout the community. His scientific contributions resulted in advances that substantively influenced our understanding of how the Earth has changed throughout time and his science, leadership and mentorship has created ripples that will continue to be influential in the years to come. Bob's outstanding 40+-year career included more than 45 research grants (>$13 million), which he used to support a diverse and numerous pool of 50 graduate students, postdoctoral scientists, and undergraduates (Appendix A).

Geology, 1999

... results demon-strate that with the proper paleotemperature equations, the oxygen isotopic com... more ... results demon-strate that with the proper paleotemperature equations, the oxygen isotopic composition of planktonic foraminifera can be used to accurately estimate ocean temperatures. Our present understanding of how past ENSOs have impacted marine climate is based ...

ABSTRACT The natural abundance of silicon isotopes (delta 30Si) in diatom frustules represents th... more ABSTRACT The natural abundance of silicon isotopes (delta 30Si) in diatom frustules represents the relative utilization of silicic acid within the waters in which they grew (De La Rocha et al., 1998). Sediment trap records of a Southern Ocean diatom bloom show that the delta 30Si values of diatoms increased throughout the course of the bloom as the silicic acid reservoir was depleted (Varela et al., 2002). Here we present the first sediment record of latitudinal variation in diatom delta 30Si values. A N-S surface sediment transect in the SE Indian Ocean shows a 0.4 \permil northward increase in delta 30Si over roughly 4 degrees latitude within the Antarctic Zone. This trend follows the northward trend of greater silicic acid utilization in surface waters and increased opal accumulation rates in the sediments within this latitudinal band. At the Antarctic Polar Front, diatom delta 30Si values decrease suggesting the presence of a dissolved silicon source in addition to northward advection. Glacial (OIS 2) delta 30Si values for diatoms south of the Polar Front tend to be lower than Holocene values (De La Rocha et al., 1998; Brzezinski et al., in press). This suggests that Antarctic Zone surface waters were relatively replete with silicic acid during the last glacial period, possibly linked to an enhanced supply of Fe and shifts in diatom nutrient uptake rates. This could allow for significant northward export of dissolved silicon for use at lower latitudes. The first sedimentary record of delta 30Si from north of the Polar Front zone shows a 0.7 \permil decrease in delta 30Si near the Subantarctic Front during the most recent glacial period. This decreased silicic acid utilization could result from an enhanced supply of silicic acid from the south or increased input of nutrients from thermocline waters.

The Oceans of Opportunity program to increase involvement of traditionally under-represented stud... more The Oceans of Opportunity program to increase involvement of traditionally under-represented students in the marine geosciences is in its final phase of track 1 funding from NSF. The program employs a tiered approach to research, teaching and outreach activities to enhance the K-12 to graduate pipeline. Partner institutions include Savannah State University, an HBCU in coastal Georgia; Adelphi University serving a minority population from NYC; the Georgia State University Bio-Bus serving the metro-Atlanta area; and the Joint Oceanographic Institutions. The Oceans of Opportunity education pipeline includes 1) service learning activities implemented by SSU marine science majors in partner public schools with high minority enrollment; 2) outreach by the Georgia State University Bio-Bus to Savannah area schools; 3) expansion of the SSU geoscience curriculum; and 4) development of activities based on models of ODP cores for use in both outreach and college teaching. Service learning thro...

$Research paper thumbnail of Biological fractionation of silicon isotopes in Southern Ocean surface waters$

Global Biogeochemical Cycles, 2004

The fractionation of silicon isotopes by diatoms during silicification (i.e., opaline cell wall f... more The fractionation of silicon isotopes by diatoms during silicification (i.e., opaline cell wall formation) provides a new tool for paleoceanographic studies of the silicon cycle. Here we examine the natural variations of the 30 Si: 28 Si ratio in silicic acid (Si(OH) 4) and biogenic silica (bSiO 2) in surface waters of the Antarctic Circumpolar Current (ACC) along 170°W. The results provide direct evidence of biologically mediated fractionation of silicon isotopes, with an enrichment factor (e) of between À1.1 and À1.9%, depending on the model employed. Comparison of the mass flux of bSiO 2 captured in sediment traps deployed in the study area with the silicon isotopic composition of that material establishes a direct linkage between diatom dynamics in surface waters and the isotopic signature of exported particles. We calculated Si(OH) 4 :NO 3 À utilization ratios from variations in silicon and nitrogen isotopic ratios in surface waters and sediment traps that agree well with direct observations of 4:1 in this region. This work supports the use of variations in silicon isotopes in sedimentary opal as a proxy for relative Si(OH) 4 utilization in surface waters.

Agu Fall Meeting Abstracts, Dec 1, 2004

To make the greatest impact on African-American participation in the geosciences it is most effic... more To make the greatest impact on African-American participation in the geosciences it is most efficient to bring programs designed to recruit future geoscientists to neighborhoods, campuses, and communities where African-Americans are actually in the majority rather than the minority. The "Natural History Interpretation Training Program" sponsored by SE-COSEE (NSF), SSU and SINERR did just that and impacted two generations of students in coastal Georgia in the process. In the first implementation of this program, ten HBCU science majors participated in an intensive week-long training program on coastal ecosystems, outdoor education, and regional internship/employment opportunities. The training session was followed by the planning and implementation of a two-day science camp for the youth of Sapelo Island, GA in which the undergraduates taught 15 children of Gullah/Geechee heritage aged 6 to 14 about the geology and ecology of their barrier island home. Key components to successfully recruiting undergraduate participants were to coordinate training activities around the college schedule to accommodate students who needed to enroll in summer courses and to base acceptance into the training program on interest rather than GPA. We facilitated the participation of campers by holding the camp on Sapelo Island, providing transportation, and charging no fees. Having HBCU students teach younger minority students served multiple purposes. It inspired the undergraduates to further their studies in science, to explore internship opportunities, and to consider careers in science education. For some it provided an opportunity to review and master material from past courses and inspired confidence in their approach to future course work. The program also piqued the curiosity of Sapelo Island youth so that they would further explore the science of their island home and, hopefully, will consider college attendance and majoring in the geosciences a natural path to follow. HBCU/MSI campuses, K-12 schools, community centers and churches with predominantly African-American membership are found throughout the U.S. and this model of one generation of students teaching a younger group can be applied to a broad range of programs and settings.

Journal of Geoscience Education, Dec 1, 2007