The difference this time is there is an entire hurricane that will move the dust further than it is now.
Dust can cause problems in that it can trap air bubbles within the mudslide. Walking over a lahar after it has been rained on is not the best idea in the world.
Think sinkhole. That might put it into context.
There probably is not much research on a lahar after a hurricane. It doesn't happen very often. But, at least Japan now has a novel place for their geologists to explore in the future.
My sincere sympathies for the families, friends and government of Japan that lost so many. Developing a method to safely explore the area after a time might even prove respectful of the families and might fulfill their wishes.
