5:15 PM - 7:15 PM
[SCG55-P07] An attempt to collect long sediment samples by modifying a multiple corer V
Keywords:multiple corer, modification, longer sediment core, bottom surface sediment
The multiple corer is an core sampling instrument that enables undisturbed collection of surface sediments (e.g., Ikehara, 1993). Normally, 60-cm-long polycarbonate pipes are set to the corer that collect approximately 30 cm of surface sediments. Recently, there has been a growing scientific demand for even longer surface sediment sampling. Under these circumstances, we have been developing the multiple coring system at the Atmosphere Ocean Research Institute, the University of Tokyo, to collect longer surface sediments using 100 cm long pipes. Along with extending the pipes, we also modified the system by extending the length of the lid arm, increasing the spring strength, and increasing the load weight. The modified system has been tested on test and research cruises, and has collected surface sediments in excess of 60 cm. A self-recording deep-sea camera has been attached to the frame of the multiple corer to take video of the bottom landing.
For example, off the coast of Kuji, northeastern Japan (4200 m water depth), three types of core samplers (the modified multiple corer, gravity corer, and piston corer) have been used to compare the recovery of marine sediments. The correlation results indicate that the long multiple core is sufficient to cover the surface sediment shortage in the uppermost layers of the piston core.
On the other hand, the long, high-strength arms associated with extending the length of the pipes posed operational challenges in that they did not accommodate in the frame and were difficult to handle during mounting and recovery.In this presentation, we will report the results of modifications we have made to our multiple corer to make it easier to operate, based on the results of previous modifications and tests. For example, by attaching a coring bit and catcher to the pipe and removing the bottom lid arm instead, the system became lighter and easier to handle. This resulted in a better recovery of sediment samples by about 10 cm. In addition, based on the modification and test results, we have tried to apply this technology to the Ashura corer to recover ~60 cm-long sediment samples.During the test cruise, we attempted to collect long samples using these improved samplers, and we will report on these results as well.
Reference
Ikehara, K. (1993) Multiple corer, a sampler for taking undisturbed surface sediments; for study on interaction between water and sediments. Journal of the Sedimentological Society of Japan, 39, 85-89.
For example, off the coast of Kuji, northeastern Japan (4200 m water depth), three types of core samplers (the modified multiple corer, gravity corer, and piston corer) have been used to compare the recovery of marine sediments. The correlation results indicate that the long multiple core is sufficient to cover the surface sediment shortage in the uppermost layers of the piston core.
On the other hand, the long, high-strength arms associated with extending the length of the pipes posed operational challenges in that they did not accommodate in the frame and were difficult to handle during mounting and recovery.In this presentation, we will report the results of modifications we have made to our multiple corer to make it easier to operate, based on the results of previous modifications and tests. For example, by attaching a coring bit and catcher to the pipe and removing the bottom lid arm instead, the system became lighter and easier to handle. This resulted in a better recovery of sediment samples by about 10 cm. In addition, based on the modification and test results, we have tried to apply this technology to the Ashura corer to recover ~60 cm-long sediment samples.During the test cruise, we attempted to collect long samples using these improved samplers, and we will report on these results as well.
Reference
Ikehara, K. (1993) Multiple corer, a sampler for taking undisturbed surface sediments; for study on interaction between water and sediments. Journal of the Sedimentological Society of Japan, 39, 85-89.