...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Volcanology and Geothermal Research >Satellite measurements of recent volcanic activity at Oldoinyo Lengai, Tanzania
【24h】

Satellite measurements of recent volcanic activity at Oldoinyo Lengai, Tanzania

机译：坦桑尼亚Oldoinyo Lengai最近火山活动的卫星测量

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Oldoinyo Lengai (OL) is the only active volcano in the world that produces natrocarbonatite lava. These carbonate-rich lavas are unique in that they have relatively low temperatures (495-590 ℃) and very low viscosity. OL has been erupting intermittently since 1983, mostly with small lava flows, pools and spatter cones (hornitos) confined to the summit crater. Explosive, ash-producing eruptions are rare, however, on September 4, 2007 the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) captured the first satellite image of an ash plume erupting from OL, which may be indicative of a new phase of more silica-rich products and explosive activity that has not occurred since 1966-1967. In the months prior to the eruption, thermal infrared (TIR) satellite monitoring detected an increasing number of thermal anomalies around OL. Data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor analyzed with the MODLEN algorithm detected more than 30 hot spots in the last week of August and first week of September 2007, some of which were from bush fires ignited by lava flows or spatter around the volcano. Higher-resolution ASTER data confirmed the location of these burn scars associated with lava flows. ASTER also detected the appearance of an anomalous hot spot at the summit of OL in mid-June with temperatures -440 ℃, the presence of several new lava flows in the crater in July and August, and on September 4 measured higher temperatures (-550 ℃) possibly suggesting a more silicate-rich eruption. ASTER spectral emissivity data were interpreted to indicate a mixture of carbonate and silicate ash in the eruption plume from September 4. Based on the analysis of both ASTER and MODIS data combined with occasional field observations, there appear to have been 2 distinct eruptive events so far in 2007: a typical natrocarbonatite eruption confined to the summit crater in June-July, and a more intense eruption in August-September consisting of natrocarbonatite lava overflowing the crater and explosive events forming ash plumes up to -5 km high, apparently consisting of a mixture of silicate and carbonate ash. OL is one of the many volcanoes in the world, and especially Africa, that is not regularly monitored with in situ instruments. Continued satellite monitoring along with studies of past thermal activity will help determine how future eruptions and ensuing hazards may be forecasted.
机译：Oldoinyo Lengai（OL）是世界上唯一产生纳碳酸盐熔岩的活火山。这些富含碳酸盐的熔岩的独特之处在于它们具有较低的温度（495-590℃）和非常低的粘度。自1983年以来，OL间歇性爆发，主要是小型熔岩流，水池和飞溅锥（hornitos）被限制在山顶火山口中。爆炸性，产生灰烬的喷发很少见，但是，2007年9月4日，先进的星载热发射和反射辐射计（ASTER）捕获了由OL喷发的烟灰羽的第一张卫星图像，这可能表明该现象进入了新的阶段。自1966-1967年以来从未发生过富含二氧化硅的产品和爆炸活动。在火山喷发前的几个月中，热红外（TIR）卫星监测发现OL附近越来越多的热异常。使用MODLEN算法分析的中分辨率成像光谱仪（MODIS）传感器提供的数据，在2007年8月的最后一周和2007年9月的第一周发现了30多个热点，其中一些是由熔岩流点燃的灌木丛火或周围的飞溅物引起的。火山。更高分辨率的ASTER数据证实了与熔岩流相关的烧伤疤痕的位置。 ASTER还检测到6月中旬在OL峰顶出现异常热点，温度为-440℃，7月和8月火山口中出现了一些新的熔岩流，而9月4日测得的高温更高（-550 ℃）可能暗示更富硅酸盐的喷发。从9月4日开始，ASTER光谱发射率数据被解释为表明喷发羽中碳酸盐和硅酸盐灰分的混合物。基于对ASTER和MODIS数据的分析以及偶发的野外观测，到目前为止，似乎已经发生了2次明显的喷发事件。 2007年：一次典型的纳碳酸盐喷发仅限于6月至7月的山顶火山口，而在8月至9月则更为强烈的喷发，其中包括由纳碳酸盐熔岩溢出火山口和爆炸事件，形成高达-5 km的烟灰柱，显然包括硅酸盐和碳酸盐灰的混合物。 OL是世界上许多火山之一，特别是非洲的许多火山，没有使用现场仪器进行定期监测。持续的卫星监测以及对过去热活动的研究将有助于确定如何预测未来的爆发和随之而来的危害。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号