Hekla Volcano, Iceland, in the 20th Century: Lava Volumes, Production Rates, and Effusion Rates
Hekla Volcano, Iceland, in the 20th Century: Lava Volumes, Production Rates, and Effusion Rates
复制标题
20 世纪的冰岛海克拉火山：熔岩量、生产率和喷出率
DOI：
--
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
J. Benediktsson
中科院分区：
文献类型：
--
作者：
G. Pedersen;J. M. Belart;E. Magnússon;O. K. Vilmundardóttir;F. Kizel;F. S. Sigurmundsson;G. Gísladóttir;J. Benediktsson
熔岩流厚度、体积和流出率为了解喷发行为及其相关变形信号提供了重要信息。根据历史立体照片生成喷发前和喷发后高程模型，以生成冰岛海克拉火山最近五次喷发的熔岩流厚度图。这些结果提供了熔岩体积的精确估计：V1947–1948 = 0.742 ± 0.138 km3、V1970 = 0.205 ± 0.012 km3、V1980–1981 = 0.169 ± 0.016 km3、V1991 = 0.241 ± 0.019 km3 和 V2000 = 0.095 ± 0.005 km3 并揭示了整个 20 世纪的可变生产率。这些新体积改善了喷发体积和喷发倾斜变化之间的线性相关性，表明倾斜可用于确定喷发体积。在喷发期间，活跃的喷口向下移动 325-480 m，表明存在 8-12 MPa 的粗略过剩压力，并且这种过剩压力的梯度在 20 世纪从 0.4 增加到 11 Pa s−1。我们认为这与喷发管道阻力增加有关。
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: V1947–1948 = 0.742 ± 0.138 km3, V1970 = 0.205 ± 0.012 km3, V1980–1981 = 0.169 ± 0.016 km3, V1991 = 0.241 ± 0.019 km3, and V2000 = 0.095 ± 0.005 km3 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.