th234_bottle

 PI:              Jennifer Young, James Murray
 of:              University of Washington
 dataset:         Isotope activity, Go-Flo bottle samples
 project/cruise:  EqPac/TT011, Survey 2
 ship:            R/V Thomas Thompson

 Thorium-234 Sampling Methodology
 Isotope Sampling Methodology
 
   
  DMO notes:

  The Murray documentation states that the samples for dissolved and particulate
  fractions were filtered using either a 0.45 or 0.50 micron filter.  Since the 
  samples were not flagged as to filter size, they all have been identified 
  as being filtered at 0.45 microns. 

  The principal investigators have arranged the data to display depth
  profiles at nominal geographic station locations. The composite profiles
  have been assembled from three or more casts within a given station/location.


  Parameter          Description                                   Units
 
  sta                station number from event log
  lat_n              nominal latitude, minus = South               degrees
  lon_n              nominal longitude, minus = West               degrees 
  depth_n            nominal depth of sample                       meters
  Ra226_SiO4         Radium-226 as determined by a Ra-Si           dpm/m3
                     regression determined from 226Ra data at the  
                     same station (see Murray documentation)
  Th234_tot          thorium-234, total                            dpm/m3
  Th234_diss_lt0.45  thorium-234, dissolved lt0.45 microns         dpm/m3
  Th234_part_gt0.45  thorium-234, particulate gt0.45 microns       dpm/m3
  Pb210_tot          lead-210, total                               dpm/m3
  Pb210_diss_lt0.45  lead-210, dissolved lt0.45 microns            dpm/m3     
  Pb210_part_gt0.45  lead-210, particulate gt0.45 microns          dpm/m3
  Po210_tot          polonium-210, total                           dpm/m3
  Po210_diss_lt0.45  polonium-210, dissolved lt0.45 microns        dpm/m3     
  Po210_part_gt0.45  polonium-210, particulate gt0.45 microns      dpm/m3     
  U238_tot           uranium-238, total                            dpm/m3
  PMC                particulate matter concentration              milligrams/m3
  
  nd indicates missing or bad data