It's a deep phreatic thermal explorer, or " DepthX" for short.

它是深潜水热探险者，简称" DepthX" 。

The lava lake and the volcano's crater has been dropping for weeks now and officials are concerned that that could lead to a phreatic eruption, when steam from ground water builds up and causes an explosion.

熔岩湖和火山的火山口已经下降了几个星期了，政府官员们担心，当来自地下的蒸汽积聚起来并引起爆炸时，可能导致潜水喷发。