God will shake the earth to get his people to do what they should

I listened to a talk by Messianic Rabbi Jonathan Cahn and near the end of his talk he disclosed that two or three modern day prophets told him that California would experience an exceptionally bad earthquake in December. From what the prophets told him and he relayed to the listeners, I think it will happen on the 30th. Jonathan doesn't seem to be a prophet himself, but has written books about prophetic messages that are in the bible. He can be heard on Youtube and the things he writes and speaks about tell about the amazing intelligence and plans of God.

The prophets told him that God is causing the natural disasters that have already come, and the upcoming big one, to shake the nation awake so that his people will be made aware that they are falling into lethargy and sinful behaviour.

I read one of Cahn's books and found it grossly overhyped. He took a three-page message and sensationalized it into 300.

Yes, America (and California especially) needs to repent. Yes, it is plausible that God will use natural disasters to draw people to Himself. However, unless the specific prophets are named and their specific words subject to review, and Cahn's message includes the gospel, it is of little value. There are far too many "prophets" whose preaching is rooted in human zeal and poor interpretation of Scripture rather than genuine prophetic unction.