Bonny, E; Thordarson, T; Wright, R; Hoskuldsson, A; Jonsdottir, I (2018). The Volume of Lava Erupted During the 2014 to 2015 Eruption at Holuhraun, Iceland: A Comparison Between Satellite- and Ground-Based Measurements. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 123(7), 5412-5426.
Abstract
The 31 August 2014 to 27 February 2015 eruption at Holuhraun created the largest lava flow field in Iceland since the 1783-1784 Laki eruption. Emplacement of a basaltic flow field of this magnitude onto an effectively flat surface (<0.1 degrees) is a rare occurrence. Lava discharge rate, a fundamental variable that controls flow field emplacement, allows us to estimate the total volume of lava erupted when integrated over time. Thus, discharge rate data are important for volcano monitoring and lava flow modeling. Here we compare discharge rates estimated using data from National Aeronautics and Space Administration's MODerate Resolution Imaging Spectroradiometer (MODIS) and the method of Harris et al. (1997a, ; 1997b, ; 2007, ), with estimates of discharge rates derived from comparing intermittent ground-based measurements of flow field volume. The time-averaged discharge rates (TADR) reveal a pulsed increase in the first few days of the eruption. Although the trends of the satellite- and ground-based discharge rates are similar, the ground-based estimates are systematically higher than the satellite-derived estimates (about 2 to 3 times higher) in the first 30days of the eruption, and relatively close (within 30%) for the next 20 days. Conversely, during the final 130days, the satellite-based estimates are systematically higher than the ground-based estimates (about 2 times higher). This difference likely arises from the assumption of the lava flow surface temperature used in the space-based calculation, which may not be entirely representative of this uniquely large and intense basaltic eruption. However, the satellite-based technique yields a total erupted volume of about 1.21km(3) in good agreement with the 1.2km(3) (84km(2)) derived from field observations and mapping.
DOI:
10.1029/2017JB015008
ISSN:
2169-9313