lava tube

基本解释

Scientists believe these holes form when the ceiling of a subterranean lava tube collapses, possibly due to a meteorite strike.
科学家认为，地下熔岩洞顶部的坍塌或流星的撞击，都是这些月球坑形成的原因。
An international team of scientists say they've discovered a protected lunar "lava tube" - a deep, giant hole - that might be well suited for a moon colony or a lunar base, CNN reported Sunday.
据美国有线新闻网3日报道，一个国际科学小组宣布，他们在月球上发现了一个又大又深的垂直"熔岩洞"，可能适宜人类移民月球或修建月球基地。
www.chinadaily.com.cn
It's unknown whether the lava is residual material that's draining through the underground tube system or if the flow is still being supplied by lava from the crater, scientists say.
科学工作者们说，不知道熔岩是否是地下管道系统排出的残留物质，或者是否火山口的熔岩仍然在提供流量。