Michael Torresan

Pacific Coastal and Marine Science Center marine geologist and sediment and core laboratories manager.  I also manage two refrigerated repositories for the archiving of core and other smaller geologic samples.


I have been with the USGS Coastal and Marine Science Center (PCMSC) since June 1976.  I have been involved in seafloor mapping and sampling of all types all over the Pacific basin from Alasks and south as far as the south Pacific (Fiji, Vanuatu, and Guadalcanal). 

Over the past 20 years my primary focus has been on updating and modernizing our PCMSC sediment and core labs.  PCMSC has a full suite of sediment and core processing labs as well as two refrigerated sample repositories. The sediment labs are outfitted with several different particle size analyzers: (1) A Beckman Coulter LS 13 320 laser diffraction particle size analyzer for particles 2mm and finer; (2) A Micromeritics SediGraph III for sedimentation analysis of particles 0.063 mm and finer ; (3) Sieves and RoTap; (4) Three 2-m tall settling tubes  and one 3-m tall settling tube for sedimentation analysis of particles 2- 0.063 mm. The 3-m tube can handle particles up to 3 mm. The sediment lab has 4 fume hoods rated for flammable and corrosive compounds as well as HF. Labware includes 5 analytical balances, 4 floor-standig large volume centrifuges, and 3 large drying ovens. We are set up for suspended seiment filtrations for the determination of sediment concentration and have internal and external pumps to accomodate many samples.  We have a carbon lab that measure total carbon, total inoganic carbon, and organic carbon. The carbon lab employs two  UIC CM5015  Coulometers, a CM5200 auto furnace, a CM5240 auto acid digester, and a  CM5230 and CM5130 manual acid digesters. We have a Micromeritics Accupyc 1340 to measure sediment density.  PCMSC has a core lab where core samples can be processed (logged and imaged),  then spilt, photographed,  described and sampled.  Analytical core processing tools include a Geotek MSCL-S multi-sensor core logger that collects non-destructive physical properties in core samples.  Properties measure with the MSCL include gamma ray density, p-wave velocity, magnetic susceptibility, and if repaired, resistivity and fractional porosity. The MSCL is outfitted with  Geotek GeoScan V and a GeoScan III high resolution line-scan cameras, and an Olympus Delta InnoveX XRF for  cm- resolution  down-core elemental analysis.  The lab is also outfitted with a Geotek RXCT high-resolution  3-and-2-D CT X-ray system for core samples and a Geotek core spllitter that handles a variety of plastic liners  of varrying diameters.   All labs have the standard labware common to most sediment and core processing labs.  This includes ample counter space, microscopes and other tools.