-
(单词翻译:双击或拖选)
Every day people come to soak in Hot Creek1, a place to rest, created by geologic2 unrest. Sudden geyser eruptions4, driven by heat from magma below the Earth surface, can change water temperatures so fast that going into the water is not recommended. But here in the eastern Sierra Mountains, few people have their minds on what's beneath their feet. The Town ofMammoth Lakes, California, and the resort known as Mammoth5 Mountain are major draws for those who love to play outdoors.
Dave Hill is a seismologist with the US Geological Survey. And he will tell you Mammoth Lakes’ shakes. Typically, several earthquakes of Magnitude 2 or less are recorded in the Mammoth Lakes region every day. It's not so much the quakes that concern Dave. It's the volcanic6 eruption3 they might foreshadow.
760,000 years ago, a catastrophic volcanic eruption spewed, approximately 600 cubic kilometers of pyroclastics. An underground magma chamber7 collapsed8, forming the crater9 known as the Long Valley Caldera. A younger line of domes10 and craters11 that make up what is called the Inyo-Mono Craters Volcanic Chain, stretches north from Mammoth Mountain at the Caldera southwest rim12. Eruptions from this valley of the volcanoes have left behind some geological wonders.
This is a young volcanic area. And some day you can see another eruption.
In May, 1980, one week after the eruption of Mount St. Helens, four strong Magnitude 6 earthquakes rocked the Long Valley Caldera. Yet it took a few years before the general public seemed to realize the volcanic hazard. While earthquakes are common precursors13 to volcanic eruptions, there were none. But the Long Valley Caldera was identified as resurgent, a growing magma-fed bulge14. Scientists are keeping a close eye on the slightest degree of movement.
We are trying to see if and when we measure distance change; if that's associated with volcanic activity.
The resort town not only lives with magma on the move, but puts it to good use. This power plant is run by water, naturally heated from below ground. There are recent signs of geologicdisturbances and volcanic activity. In 1990, trees on Mammoth Mountain Volcano began dying. Since then, more than 150 acres of trees have been killed by large amounts of carbon dioxide that is released into the soil by magma, suffocating15 the tree roots.
No one doubts this volcanic system will erupt again. But seismologist Dave Hill says thepersistent unrest from this youthful volcanic system has finally been put in perspective. Today the geology of the Long Valley Caldera is monitored by scientists, respected by residents, and admired and appreciated by everyone. The US GS has established procedures and a response plan to promptly16 alert the public well in advance of a possible eruption. But the chances of it happening in the coming years are very, very small.
1 creek | |
n.小溪,小河,小湾 | |
参考例句: |
|
|
2 geologic | |
adj.地质的 | |
参考例句: |
|
|
3 eruption | |
n.火山爆发;(战争等)爆发;(疾病等)发作 | |
参考例句: |
|
|
4 eruptions | |
n.喷发,爆发( eruption的名词复数 ) | |
参考例句: |
|
|
5 mammoth | |
n.长毛象;adj.长毛象似的,巨大的 | |
参考例句: |
|
|
6 volcanic | |
adj.火山的;象火山的;由火山引起的 | |
参考例句: |
|
|
7 chamber | |
n.房间,寝室;会议厅;议院;会所 | |
参考例句: |
|
|
8 collapsed | |
adj.倒塌的 | |
参考例句: |
|
|
9 crater | |
n.火山口,弹坑 | |
参考例句: |
|
|
10 domes | |
n.圆屋顶( dome的名词复数 );像圆屋顶一样的东西;圆顶体育场 | |
参考例句: |
|
|
11 craters | |
n.火山口( crater的名词复数 );弹坑等 | |
参考例句: |
|
|
12 rim | |
n.(圆物的)边,轮缘;边界 | |
参考例句: |
|
|
13 precursors | |
n.先驱( precursor的名词复数 );先行者;先兆;初期形式 | |
参考例句: |
|
|
14 bulge | |
n.突出,膨胀,激增;vt.突出,膨胀 | |
参考例句: |
|
|
15 suffocating | |
a.使人窒息的 | |
参考例句: |
|
|
16 promptly | |
adv.及时地,敏捷地 | |
参考例句: |
|
|