Name: Rodolfo van der Laat
Position: Researcher
Organization: National Observatory of Volcanology and Seismology
Year of JICA Volcanology Course: 1990
Activities:
Geodetic Monitoring of Active Volcanoes, as part of a broad Program that also cover gas geochemistry and volcano seismology. Geodetic monitoring has been established since 1981 on five the main active volcanoes of Costa Rica: Rincón de la Vieja, Arenal, Poás, Irazú and Turrialba. Techniques applied include precise geometric and trigonometric leveling, geodetic netwoks, electronic distance arrays, tilt and GPS. The networks are reoccupied as frequently as possible and continuous monitoring has been reinforced with GPS and tiltmetry.
EDM observation site at the summit of Irazú volcano. From this site precise distances are observed to several fixed reflectors around the crater area
Good Practice
A recent experience is related with the phreatic activity at Poás volcano that began on March 24, 2006 and ended three weeks later.
The documentation and observation of the eruptive activity was increased applying the known techniques of volcano monitoring: volcano seismology, gas geochemistry and volcano geodesy. Recommendations to the authorities were given and they decided to close, for one week, the National Park, that includes the crater area. Poás volcano is the most visited National Park in Costa Rica and the visitors reach the summit area by paved road and the crater rim after a short walk. Most of the effects of the activity are related with the emission of acid rain. This illustrates a case that is not catastrophic, but the visitors and Park staff health were protected.
The knowledge of the current volcanic activity is the base to recommend and decide protection measures of lives, despite the economic reduction in this case, due to the cease of the National Park activities and related commercial activities.
Meeting with Poás volcano National Park staff. They learned about the types of volcano activity, monitoring techniques and specific volcano hazards