Hekla Volcano, Iceland, in the 20th Century: Lava Volumes, Production Rates, and Effusion Rates

• Published in: Geophysical Research Letters
• Main Authors: Pedersen, G. B. M., Belart, J. M. C., Magnússon, E., Vilmundardóttir, O. K., Kizel, F., Sigurmundsson, F. S., Gísladóttir, G., Benediktsson, J. A.
• Other Authors: Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: CCSD 2018
• Subjects: Hekla; Iceland; lava volumes; production rates; effusion rates; stereo photogrammetry; high-resolution digital elevation models; [SDU]Sciences of the Universe [physics]
• Online Access: https://insu.hal.science/insu-04835475; https://insu.hal.science/insu-04835475v1/document; https://insu.hal.science/insu-04835475v1/file/Geophysical%20Research%20Letters%20-%202018%20-%20Pedersen%20-%20Hekla%20Volcano%20Iceland%20in%20the%2020th%20Century%20Lava%20Volumes%20Production.pdf; https://doi.org/10.1002/2017GL076887

International audience Lava flow thicknesses, volumes, and effusion rates provide essential information for understanding the behavior of eruptions and their associated deformation signals. Preeruption and posteruption elevation models were generated from historical stereo photographs to produce the lava flow thickness maps for the last five eruptions at Hekla volcano, Iceland. These results provide precise estimation of lava bulk volumes: V 1947-1948 = 0.742 ± 0.138 km 3 , V 1970 = 0.205 ± 0.012 km 3 , V 1980-1981 = 0.169 ± 0.016 km 3 , V 1991 = 0.241 ± 0.019 km 3 , and V 2000 = 0.095 ± 0.005 km 3 and reveal variable production rate through the 20th century. These new volumes improve the linear correlation between erupted volume and coeruption tilt change, indicating that tilt may be used to determine eruption volume. During eruptions the active vents migrate 325-480 m downhill, suggesting rough excess pressures of 8-12 MPa and that the gradient of this excess pressure increases from 0.4 to 11 Pa s -1 during the 20th century. We suggest that this is related to increased resistance along the eruptive conduit.