Magnetic properties of ODP Site 191-1179 sediments

As reported by Shipboard Scientific Party (2001b, doi:10.2973/odp.proc.ir.191.104.2001) in the Site 1179 chapter of the Initial Reports volume, Leg 191 Site 1179 is located on abyssal seafloor northwest of Shatsky Rise, ~1650 km east of Japan. This part of the Pacific plate was formed during the Early Cretaceous, as shown by northeast-trending M-series magnetic lineations that become younger toward the northwest (Larson and Chase, 1972, doi:10.1130/0016-7606(1972)83[3627:LMEOTW]2.0.CO;2; Sager et al., 1988, doi:10.1029/JB093iB10p11753; Nakanishi et al., 1989, doi:10.1029/1999JB900002). The site is situated on magnetic Anomaly M8 (Nakanishi et al., 1999, doi:10.1029/1999JB900002), corresponding to an age of ~129 Ma and the Hauterivian stage of the Early Cretaceous (Gradstein et al., 1994, doi:10.1029/94JB01889; 1995). The sediments recovered at Site 1179 are split into four lithostratigraphic units based on composition and color (Shipboard Scientific Party, 2001b, doi:10.2973/odp.proc.ir.191.104.2001). Unit I (0-221.52 meters below seafloor [mbsf]) is a dominantly olive-gray clay- and radiolarian-bearing diatom ooze. Unit II (221.52-246.0 mbsf) is a yellowish brown to light brown clay-rich and diatom-bearing radiolarian ooze. Unit III (246.0-283.53 mbsf) is composed of brown pelagic clay. Unit IV (283.53-377.15 mbsf) is composed of chert and some porcellanite; any softer sediments present were washed out of the core barrel by the fluid circulating during the coring process.

(Table 2) Age determination of Southern Ocean sediments

The silicic acid leakage hypothesis (SALH) predicts that during glacial periods excess silicic acid was transported from the Southern Ocean to lower latitudes, which favored diatom production over coccolithophorid production and caused a drawdown of atmospheric CO2. Downcore records of 230Th-normalized opal (biogenic silica) fluxes from 31 cores in the Pacific sector of the Southern Ocean were used to compare diatom productivity during the last glacial period to that of the Holocene and to examine the evidence for increased glacial Si export to the tropics. Average glacial opal fluxes south of the modern Antarctic Polar Front (APF) were less than during the Holocene, while average glacial opal fluxes north of the APF were greater than during the Holocene. However, the magnitude of the increase north of the APF was not enough to offset decreased fluxes to the south, resulting in a decrease in opal burial in the Pacific sector of the Southern Ocean during the last glacial period, equivalent to approximately 15 Gt opal/ka1. This is consistent with the work of Chase et al. (2003, doi:10.1016/S0967-0645(02)00595-7), and satisfies the primary requirement of the SALH, assuming that the upwelled supply of Si was approximately equivalent during the Holocene and the glacial period. However, previous results from the equatorial oceans are inconsistent with the other predictions of the SALH, namely that either the Corg:CaCO3 ratio or the rate of opal burial should have increased during glacial periods. We compare the magnitudes of changes in the Southern Ocean and the tropics and suggest that Si escaping the glacial Southern Ocean must have had an alternate destination, possibly the continental margins. There is currently insufficient data to test this hypothesis, but the existence of this sink and its potential impact on glacial pCO2 remain interesting topics for future study.

Women's Volleyball Team, 1995, UM

Front Row: Colleen Miniuk, Sarah Jackson, Darlene Recker, Shannon Brownlee, Suzy O'Donnell, Ramona Cox, Kristen Ruschiensky, administrative assistant Susan McAvoy

Back row: Meg Akehi, assistant coach Amy Verhoeven, Chereena Tennis, head coach Greg Giovanazzi, Shareen Luze, Karen Chase, Linsey Ebert, Jeanine Szczesniak, Jane Stevens, Erin McGovern, Linnea Mendoza, assistant coach Mora Kanim, athletic medicine Keli Coughlin.

Women's Volleyball Team, 1996, UM

Front Row: athletic trainer Keli Coughlin, assistant coach Irene Renteria, head coach Greg Giovanazzi, assistant coach Mora Kanim, student trainer Suzanne Dolembo.

Middle Row: Erin McGovern, Ramona Cox, Sarah Jackson, Colleen Miniuk, Shareen Luze, Darlene Recker, Kristen Ruschiensky, Jane Stevens, Chereena Tennis, Linnea Mendoza, Meg Akehi.

Back Row: Carrie Ricker, Kiley Hansen, Shari Turner, Linsey Ebert, Anne Poglits, Jennifer Allen, Karen Chase, Maggie Cooper, Jeanine Szczesniak.

Women's Volleyball Team, 1997, UM

Front Row: Sarah Jackson, Darlene Recker, Linnea Mendoza.

Second Row: athletic trainer Keli Coughlin, assistant coach Irene Renteria, Missy Akey, Chereena Tennis, Shawna Olson, Jane Stevens.

Third Row: assistant coach Aimee Smith, Jenny Schroeder, Sarah Behnke, Linsey Ebert, Karen Chase, Maggie Cooper, Alija Pittenger.

Back Row: Jeanine Szczesniak, C.C. Pryor, Joanna Fielder, Anne Poglits, Annie Maxwell, Shari Turner.

Not pictured: Carrie Ricker.

Women's Volleyball Team, 1998 UM

Front Row: Nicole Kacor, Amy DeCinces, Jenny Lachapelle, Shannon Melka.

Middle Row: student athletic trainer Anna Napolitano, Jeanine Szczesniak, Chereena Tennis, Jane Stevens, Linsey Ebert, Karen Chase, Maggie Cooper, athletic trainer Joel Pickerman

Back Row: assistant coach Aimee Smith, Irene Renteria - assistant coach, Alija Pittenger, C.C. Pryor, Sarah Behnke, Katrina Lehman, Anne Poglits, Joanna Fielder, Annie Maxwell, Carrie Ricker, Shawna Olson, undergraduate assistant coach Ramona Cox, head coach Greg Giovanazzi

Legislative history of recent primary safety belt laws.

National Highway Traffic Safety Administration, Office of Research and Traffic Records, Washington, D.C.

The Department of Transportation long-range forecast model. Final report.

Transportation Department, Office of Intermodal Transportation, Washington, D.C.

Principles of radioisotope methodology /

Includes bibliography.

Principles of radioisotope methodology /

Mode of access: Internet.