Thursday marks the anniversary of the last Cascadia earthquake. State and local officials say it's a good reminder to make sure you're prepared for the next one. It's been 323 years since that megaquake hit the Oregon Coast on January 26th, 1700. It had an estimated magnitude of 8.7 to 9.2. Officials say the severe shaking caused the land to drop by about 6 feet. A tsunami arrived ashore about 15-to-25 minutes later. While experts can't predict when the next "big one" will occur, they agree the region is overdue for another catastrophic earthquake and tsunami. Officials encourage everyone to mark tomorrow's anniversary by creating a disaster plan and making sure you're prepared for an emergency.