Profiles of dissolved and particulate thorium isotopes in the water column of coastal Southern California

Details Profiles of dissolved and particulate thorium isotopes in the water column of coastal Southern California Profiles of dissolved and particulate thorium isotopes in the water column of coastal Southern California

Sep 1987

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1987e%26psl..85....1h&link_type=abstract

Earth and Planetary Science Letters, Volume 85, Issue 1-3, p. 1-10.

Physics

13

Scientific paper

Profiles of 234Th, 232Th, and 230Th in the Santa Monica Basin were measured. 234Th in the upper part of the water column suggests that the residence time of dissolved 234Th, with respect to adsorption onto and removal by particles, increases with depth, from 3-4 weeks at the surface to > 5 months below the euphotic zone. The partition of 234Th between dissolved and particulate forms points to a residence time of 4-7 days for particulate 234Th in the surface euphotic zone. Rapid removal of particulate 234Th from the surface water precludes the possibility of an adsorption-desorption equilibrium state between dissolved and particulate 234Th. Based on the 230Th data, the overall residence time of dissolved Th in the water column is estimated at 5-6 years. Both dissolved 230Th and 232Th profiles exhibit higher concentrations at the surface than immediately underneath, suggesting a terrestrial input for them. From the surface to the bottom of the water column, the concentration of dissolved 232Th decreases by a factor of 3-4, and the dissolved 230Th/232Th activity ratio increases by a factor of about five (from 2-3 to 9-12). This reflects the surface source of the terrestrial end-member and its removal at depth. On the average about 6% of the 234Th, 25% of the 230Th, and 50% of the 232Th were found in the particulate form, which is as expected and relates to their respective sources, to the difference in radioactive decay half-life, and to the kinetics of the scavenging process.

Affiliated with

Also associated with

No associations

Rating

Profiles of dissolved and particulate thorium isotopes in the water column of coastal Southern California does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Profiles of dissolved and particulate thorium isotopes in the water column of coastal Southern California, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Profiles of dissolved and particulate thorium isotopes in the water column of coastal Southern California will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1673295