In other words, they can never make a reliable prediction over severity of an eruption, or for that matter, whatever it will even bream the surface.

For that matter는 어떻게 해석해야대나요?

Prime example would be the prediction of the 1980 Mt. St. Helebs eruptions of which the examct timing and magnitude
not only stunned the experts, and but most critically it saved around 20,000 lives
despite the fact that 57 people were killed.

Of which가 관대인가요????
Not only but also가 보이는데
But most부터 해석이 전혀 안대고 구조도 파악이 안대요 ...