The 1993 Lascar pyroclastic flow imaged by JERS-1
The 1993 Lascar pyroclastic flow imaged by JERS-1
复制标题
JERS-1 拍摄的 1993 年拉斯卡火山碎屑流
DOI：
10.1080/01431169608948753
复制
发表时间：
1996
影响因子：
3.4
通讯作者：
D. Rothery
中科院分区：
文献类型：
--
作者：
A. Denniss;A. Harris;R. Carlton;P. Francis;D. Rothery
2.拉斯卡尔火山是智利安第斯山脉的一座5450米高的火山（图2插图）。在过去的几十年里，拉斯卡火山一直很活跃，其特征是山顶火山口系统内的熔岩圆顶挤出（图2），不时有火山灰爆发，产生局部火山碎屑流和广泛的火山灰沉积。拉斯卡尔历史上最大规模的喷发发生在1993年4月18日晚，持续了两天（GVN 1993）。在这段时间里，火山口上方升起了无数的火山灰柱，并爆发了许多火山碎屑流。最大的火山灰柱达到火山口上方20- 22公里处，导致轻灰落下（深度约0.1毫米），远至阿根廷布宜诺斯艾利斯，距离拉斯卡东南1500公里。1993年4月20日，一个10公里高的火山灰柱坍塌，导致最大的火山碎屑流就位，沿着拉斯卡西北侧延伸了7.5公里。四个较小的叠加火山碎屑流也侵位在火山口边缘的ESE。它们延伸了3-4km，到达Pampa Lejia平原，厚度为1 '2 - 1' 5 m（GVN 1993），图2.3。由于拉斯卡尔的地理位置偏远，自1984年以来，遥感技术为这一监测较差的火山提供了最连续的信息来源（Rothery等人，1988年; Glaze等人，1989年）。特别是，大地卫星专题成像仪数据被用于监测活动火山口内的热事件，探测与熔岩穹丘挤出有关的短波红外辐射（Oppenheimer等人，1993年）。GOES和AVHRR等其他传感器也被用来探测、定位和监测喷发羽流（Glaze等人，1989年）。由于Lascar是偏远和不经常访问，这样的远程
2. Lascar and the April 1993 eruption Lascar is a 5450m high volcano in the Chilean Andes (figure 2 inset). Over the past several decades Lascar has been continually active, characterized by lava dome extrusion within the summit crater system (figure 2), punctuated by periodic explosive ash eruptions creating localized pyroclastic flows and widespread ash fall deposits. The largest historical eruption of Lascar occurred late on 18 April 1993 and lasted for two days (GVN 1993). During this time numerous ash columns rose above the crater and a number of pyroclastic flows were erupted. The largest ash column reached 20-22km above the crater, resulting in light ash falls «0· 1mm in depth) as far away as Buenos Aires, Argentina, 1500km south-east of Lascar. Collapse of a 10km high ash column on 20 April 1993 resulted in the emplacement of the largest pyroclastic flow, which extended 7· 5km down the NW flank of Lascar. Four smaller superimposed pyroclastic flows where also emplaced ESE of the crater rim. These extended for 3-4km and reached the Pampa Lejia plain, where they were 1'2-1'5m thick (GVN 1993), figure 2.3. Remote sensing of volcanoes using JERS-l OPS Because of the remote geographical location of Lascar, remote sensing techniques have, since 1984, provided the most continuous source of information for this otherwise poorly monitored volcano (Rothery et al. 1988, Glaze et al. 1989). In particular, Landsat Thematic Mapper (TM) data have been used to monitor thermal events within the active crater, detecting short wavelength infrared radiance (SWIR) associated with lava dome extrusion (Oppenheimer et al. 1993). Other sensors such as GOES and AVHRR have been used to detect, locate and monitor eruption plumes (Glaze et al. 1989). Since Lascar is remote and infrequently visited, such remotely