Tairua Beach, New Zealand and Cedar Island, Virginia are more than 8,000 miles apart, yet when it comes to understanding coastal storm erosion they are much closer than you might suspect. Partners in an international research initiative, teams from the New ZealandNational Institute of Water and Atmospheric Research (NIWA), and the VIMS Department of Physical Sciences collaborated in the deployment of three instrumented pods off the North Island of New Zealand in mid–February. Two of the pods pictured in the video to the left are maintained by VIMS, while the third pod ALICE is owned and operated by NIWA. Co-principal investigators on the joint project are VIMS Director Dr. Don Wright and former VIMS graduate student now NIWA researcher Dr. Malcolm Green.

The teams'project has benefited from a meteorological event in the form of a tropical cyclone named Pamela (for a barometric pressure chart movie of Pamela's movements, click here). During early March, this major storm passed the Coromandal Peninsula on the north coast of New Zealand and created the waves and currents the research team hoped to capture. This storm was great news for Dr. Don Wright, Bob Gammisch, Grace Battisto, Todd Nelson, Art Trembanis and Wayne Reisner from VIMS, and for Rick Liefting, Rod Budd, John Hawken and Ian McDonald from NIWA, who participated in the assembly and deployment of the seabed tripods on the sea floor just off Tairua Beach a few weeks prior to the storm. Also involved in the study are Dr. Terry Hume, Dr. Karin Bryan (both from NIWA) and Dr. Chris Vincent of the University of East Anglia.

The Tairua Beach tripod study by NIWA/VIMS is integrated with a larger ongoing New Zealand research program known as COSMOS funded by the Foundation for Research Science and Technology (FRST) which involves the study of sand transport in disconnected embayed systems. Tairua forms one of the embayed systems that NIWA is interested in studying. The COSMOS project at Tairua is being headed up by Dr. Karin Bryan of NIWA.

In describing the project, Co-PI Green said "In this experiment, we are able to simultaneously place instruments on different seabed types offshore from the surfzone, which gives us a view of the range and complexity of sediment-transport processes at work. Our aim is to assimilate that complexity in numerical models of sediment transport. We will use those models to depict patterns of sand movement between the beach and offshore and between adjacent embayed compartments, and we will relate patterns of sand movement to erosion hazards along the shoreline." Already, side-scan sonar maps of the seabed collected in September and again in February have identified complex patterns of seabed texture including megaripple coarse sand patches.

For the VIMS team, having the pods deployed by helicopter was a new experience. "Seeing the tripods take off into the air was exciting. We also had some anxious moments," said Trembanis, a Ph.D. student involved in the project. "All three tripods, each weighing nearly two thousand pounds, were deployed in less than 30 minutes from start to finish. Our tripods have previously been confined to the deck of a research vessel during deployment and recovery. The NIWA group regularly uses helicopters on research projects." Helicopter deployments are an expedient, safe and cost effective way to deploy instruments in remote locations such as this site in New Zealand.

ALICE has been operating for NIWA in a range of estuarine and coastal (shoreface and inner shelf) environments for the past 6 years. The VIMS tripods have been used extensively at other sites in recent years including Duck, NC, Cedar Island, VA and off the Eel River in California to capture information about the intensity of waves and currents acting on the seabed and to measure the amount of sand that is moved around by the forces. Their efforts have paid off in that they captured the “Perfect Storm” in 1991, major storms off Duck in 1992 and 1994; storms and a major flood off the Eel River in California in 1995-1996; and major storms that occurred in 1996-1997 in both California and on Cedar Island, Virginia.

The NIWA/VIMS project grew out of a desire to further cooperation between the two institutes that was formalized recently by a General Cooperation Intention Agreement. According to Dr. Green who received his PhD from VIMS in 1987, "This project (is) very important for our science and for our developing relationship with VIMS. By pooling equipment and bringing scientists and technicians from the two Institutes together, we expand our capabilities and stimulate new thinking on coastal processes." The project entitled "The Role of Spatially Complex Shoreface Roughness in Sediment Transport and Deposition: A New Zealand Case Study and Model Development" is sponsored by the National Science Foundation through Grant INT-9987936. Wright and his team will return to Tairua Beach in late March to rejoin the team from NIWA who have been busy with other beach and estuarine studies in the area. The two teams will retrieve the tripods, and begin the process of analyzing the results from the storm experiment.