- IODP at MARUM
- Partner to the ECORD Science Operator
- Offshore core curation and measurements
- Initial sampling and analyses
- Interstitial pore waters (IW)
Interstitial pore waters (IW)
Interstitial pore waters (IW)
In case of soft sediment recovery interstitial waters for geochemical analysis samples are generated from the whole round samples removed from suitable material on the drillfloor. In less consolidated sediments at the top of a borehole, IW samples are generally 5 cm long (176 cc). The size of the sample may be increased as the sediment becomes more lithified with depth. In addition, pore-water acquisition with the new generation of “Rhizone pore water samplers” will be used on MSP expeditions in soft parts of the sedimentary records. The SAC and the geochemists work together to come up with an IW sampling plan that best meets the needs of the shipboard party. The IW sample may be recorded at the core entry computer via ExpeditionDIS.
IODP pore water sample splits
Parameter | Sequence | Amount | Unit | Type | take with | take from | Container | Receiver | Prepare | Storage |
CH4, HC | 1 | 5 | mL | sed | cut 5 mL syringe | cut face | 20 mL crimp seal | 10 mL saturated NaCl solution with sodium azide | receiver pipette 20 mm crimper caps vials rack | shake and freeze -20°C upside down |
2 | a | IW | rhizon | Whole core | 20/50 mL syringe | rhizons | cap syringe, keep cool until spliting | |||
2 | b | IW | squeezer | 5 - 10 cm WCR | 20/50 mL syringe | squeezer | cap syringe, keep cool until splitting | |||
pH, alkalinity | 3 | IW | 2 mL cup | 1.5 mL Eppendorf cup | label and keep cool at 4°C | |||||
salinity | 4 | IW | 2 mL cup | - | refractometer | |||||
NH4 | 5 | 0.5 | mL | IW | 1 mL syringe | 2 mL cup | loop | Ammonia detector (teflon tape gas sep.) | discard | |
Cations | 6 | 4 | mL | IW | IW syringe | ampoule / Nalgene 4 mL | 40 µL s.pure HNO3 65% | vials rack nitric acid pipette | label and keep cool at 4°C | |
Anions | 7 | 4 | mL | IW | IW syringe | ampoule / Nalgene 4 mL | vials rack | label and keep cool at 4°C | ||
δ 13C | 8 | 1.8 | mL | IW | IW syringe | 1.8 mL crimp cap | 20 µL HgCL2 solution, no headspace ! | receiver pipette 13mm crimper caps vials rack | label and keep cool at 4°C | |
H2S, 34S |
9 | mL | IW | hand pipette | 2 mL cup | 2 mL srew cap wheaton | 20 µL 50mM Zn-acetate solution | receiver solution, vials, rack | label and keep cool at 4°C | |
δ 18O | 10 | mL | IW | IW syringe | 1.8 mL crimp cap | no headspace ! | vials rack, 13 mm crimper caps | label and keep cool at 4°C | ||
Trace elements | 11 | mL | IW | IW syringe | Nalgene 4 mL | 40 µL s.pure HNO3 65% | vials rack nitric acid pipette | label and keep cool at 4°C | ||
DOC, PO4 | 12 | mL | IW | IW syringe | ampoule | vials rack | label and keep cool at 4°C | |||
Residual | 13 | mL | IW | IW syringe | 20 mL Greiner / 15 mL Nalgene | label and keep cool at 4°C |