Motion of Kilauea Volcano during sustained eruption from the Puu Oo and Kupaianaha Vents, 1983–1991
Motion of Kilauea Volcano during sustained eruption from the Puu Oo and Kupaianaha Vents, 1983–1991
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1983-1991 年 Puu Oo 和 Kupaianaha 喷口持续喷发期间基拉韦厄火山的运动
DOI：
10.1029/93jb01819
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发表时间：
1993
影响因子：
--
通讯作者：
M. Sako
中科院分区：
文献类型：
--
作者：
P. T. Delaney;A. Miklius;T. Árnadóttir;A. Okamura;M. Sako
从1983年1月到1991年，基拉韦厄火山几乎连续喷发。虽然山顶开始下沉，在裂谷带岩脉侵入，引发了这次喷发，显着稳定的地表运动开始于1983年底后，6.6级地震下的斜坡附近的莫纳罗亚火山，并持续到1990年底的短暂的上东裂谷带地震群的开始。在这7年中，山顶和上裂谷带分别下沉了10-11和4-8厘米/年，山顶基线收缩了6厘米/年。从山顶向北到莫纳罗亚山的基线以每年7厘米的速度延伸，从山顶以南到莫纳罗亚山的基线以每年4厘米的速度延伸。这种延伸的大部分是不一致的变形所造成的唯一的高峰岩浆水库崩溃，更有可能反映裂谷作为南翼的火山移动到海从山顶和裂谷带。在离峰顶更远的地方，穿过南翼的基线延伸至2 cm/yr−1，南翼的验潮仪上升了2 cm/yr−1;在离峰顶40-50 km处的较低的东部裂谷带下沉了约2 cm/yr−1。因此，基拉韦厄的运动大致上与沿着低角度南翼断层的滑动相一致，产生的沉降集中在山顶和断层后面的裂谷系统，并沿着断层前面的沿海南翼隆起。联合收割机这些元素的位错模型显示，基拉韦厄的大部分沉积物向海迁移，产生的地表运动沿着南翼高达6 cm/年。1989年的6.1级地震使这些运动沿着东南翼，产生了超过25厘米的向海位移，在震中以东15公里处，下东裂谷带以南的沉降高达24厘米。与1975年的7.2级南翼地震不同，1989年的地震之前既没有山顶岩浆库膨胀，也没有裂谷带岩脉侵入和伴随的南翼压缩。变形可能是由火山覆盖层的重量和裂谷系统内持续的扩张和滑动造成的。
Kilauea erupted almost continuously from January 1983 through 1991. Although the summit began subsiding during the rift zone dike intrusion that initiated this eruption, remarkably steady ground surface motions began in late 1983 after a magnitude 6.6 earthquake beneath the slopes of nearby Mauna Loa volcano and continued until the onset of brief upper east rift zone earthquake swarms in late 1990. During these 7 years the summit and upper rift zones subsided up to 10–11 and 4–8 cm yr−1, respectively, and summit baselines contracted up to 6 cm yr−1. Baselines directed northward from the summit to stations on Mauna Loa extended at rates up to 7 cm yr−1, and a baseline from south of the summit to Mauna Loa extended 4 cm yr−1. Much of this extension is inconsistent with deformation caused solely by summit magma reservoir collapse and more likely reflects rifting as the south flank of the volcano moved seaward from the summit and rift zones. Farther from the summit, baselines crossing the south flank extended up to 2 cm yr−1, and a south flank tide gauge rose 2 cm yr−1; the lower east rift zone, 40–50 km from the summit, subsided about 2 cm yr−1. Motion on Kilauea, then, is broadly consistent with slip along low-angle south flank faults, generating subsidence that is focused at the summit and along the rift system behind the faulting and uplift along the coastal south flank ahead of it. Dislocation models that combine these elements show that much of Kilauea's edifice migrated seaward, producing ground surface motions along the south flank of up to about 6 cm yr−1. The magnitude 6.1 earthquake of 1989 punctuated these motions along the eastern south flank, producing more than 25 cm of seaward displacement and, 15 km east of the epicenter, up to 24 cm of subsidence south of the lower east rift zone. Unlike the magnitude 7.2 south flank earthquake of 1975, the 1989 event was preceded neither by summit magma reservoir inflation nor by rift zone dike intrusions and accompanying compression of the south flank. Deformation was probably caused by the weight of the volcanic overburden and by ongoing dilation and slip within the rift system.