Lahar Observations in New Zealand

AP No. 072: New Zealand Lahar CASE STUDY

Campbell Scientific dataloggers and camera key to historic recording of mud flow

All of our years of effort have paid Knowing when and where to place Case Study Summary off. We have collected a world-class instruments is a tough guess, as the dense, rock-filled lahars often dam- data set that will make this the Application: best-studied lahar ever. age or destroy instruments in their Monitoring lahar mud flow from Dr. Vern Manville, GNS Science path. Because of this, Dr. Manville volcanic crater lake after tephra and his team from New Zealand’s dam breaks Dr. Manville’s words describe the GNS Science agency and Massey success of a unique study of a volca- Location: University considered it rare good New Zealand nic rock slide and mud flow, called fortune to be able to set up monitor- a lahar. When a volcanic crater fills Contracting Agencies: with rainwater, the walls of the crater GNS Science sometimes collapse, releasing a Products Used: catastrophic flood of mud and rock. CC640, CR800, CR1000 The word lahar comes from Java in Contributors: Indonesia, where the frequency of Roger Hardy volcanoes and the abundance of Scott Technical Instruments rain make these mud flows a com- Measured Parameters: Video recording of dam breaking; mon occurrence. Lahars are usually crater lake level measured with hard to study because their occur- bubbler unit; flow level measured rence is unpredictable and their flow with radar and pressure transducers is violent.

More info: 435.227.9120 campbellsci.com/new-zealand-lahar ing equipment in advance of a recent camera connected to a CR1000 data- Dr. Manville said, “The gear worked large-scale lahar at Crater Lake on logger captured the dramatic col- perfectly, and the weather was just Mount Ruapehu. The volcano was lapse of the crater wall and the flood good enough to allow us to see the close enough to the study centers of lake waters through the opening. collapse of the dam and the Crater that extensive preparations could be Sensors and CR1000 and CR800 Lake pouring out through the breach.” made at the site. The path of the ex- dataloggers were positioned down Scientists will spend months gather- pected flow was predictable enough the path of the lahar to collect data ing follow-up data, and years analyz- to allow placement of sensors where about its level and sediment content. ing it all. The intensive study of New they could gather the most informa- The instruments had to be mounted Zealand’s Ruapehu lahar may enable tion without being destroyed. on hardened towers or canyon walls scientists to better predict and pre- to survive the tremendous force of pare for these dangerous phenomena. Campbell Scientific gear was a big the lahar. part of the effort. Our CC640 digital