One thing that the book really doesn't deal with is the very large-scale slumping and sliding that has affected all of the islands. Partly this is because most of the confirming evidence for these slides has been discovered in the past 10 years. We now know that most islands have suffered major landslides that have removed very large pieces of the volcanoes Figure 1 shows locations of major slides off the islands. The slides are caused by steep slopes and volcanic and seismic activity. The young slopes of the volcanoes are very steep, and become even steeper when the flanks of the volcanoes are inflated by volcanic actvity.
Earthquakes can then shake the ground and cause a failure.
The current thinking is that the slumps occur during the major shield building process. Once volcanism stops, the islands are probably stable. Kilauea is buttressed on the north by Mauna Loa, but south flank is free surface. The southflank is moving at a constant rate of about 10 cm per year to the southeast. A large earthquake occurred in 1975 in Kalapana.