Thanks for explaining


The only thing I'd add is that deformation shows signs of activity, even when the seismograph doesn't. Slumping, in this case, represents a magma tube that has either emptied or somehow the ground itself has dropped in some significant way...possibly through the exit of ground water, oil, natural gas, etc.


When deformation reaches a certain point, land slides occur or sinkholes form. Some other things can happen as well, but this is most common. Now...on an island like Hierro, a slide can have devestating consequences. That's one reason why we're watching these events so closely.