Volcanic tremor is due to the oscillation of magmatic gas or due to the crater-wall downfall . 火山地震由火山气体振荡或火山口内壁崩塌引起。
Volcanic tremor is due to the oscillation of magmatic gas or due to the craterwall downfall . 火山地震由火山气体振荡或火山口内壁的崩塌引起。
Volcanic tremor is due to the oscillation of magmatic gas or due to the crater-wall downfall . 火山地震由火山气体振荡或火山口内壁的崩塌引起。
At the galapagos rift, volcanic activity beneath two geologic plates renews the earth's crust . 在加拉帕戈斯裂谷，两地质板块下面的火山活动使地壳更新。
Present evidence points to a volcanic origin far in the past for the majority of the craters . 最近的资料表明，现在比过去更倾向于火山是大多数环形山的起因。
The only apparent building process that the early earth scientists could detect was volcanic activity . 早期地质学家所能发现的唯一明显的构造作用就是火山活动。
Fossils embedded in or between the volcanic layers can thus be dated by this method with great accuracy . 火山岩层间夹合的化石层可使这种测定年龄的方法极为精确。
The year after its eruption in 1980, spruce seedlings were coming up in the volcanic ash on mt. st. helens . 1980年圣海伦火山爆发之后，仅过一年，云杉幼苗就在火山灰上生长起来了。
Craters resembling those on the moon are produced on the earth both by volcanic activity and by meteoric impact . 由于火山爆发和陨星的撞击，类似于月球上的环形山地在地球上产生了。
The concept of this self-sealing process broadens the likelihood of cap rocks with low permeability occurring in volcanic areas . 自封密过程这一概念使得火山区也可能出现渗透性能很低的盖层。
