Indeed it can change very quickly. In the Gulf of Mexico on the northern tip of the Yucatan Peninsula is a crater 180 kilometers across. It is the site where the Chucxulub asteroid struck. This asteroid was over 10 kilometers across, the size of a small city. It would have been travelling at a rate of around 40,000 mph upon impact. It is estimated that it sent a splash of mud and water up aproximately 70,000 feet, and a tsunami around 5,000 feet in height washed across the North American continent, while tsunamis up to 1,500 feet high struck the continents of Europe and Africa. The disturbance to the sea floor at the site of impact, and the disturbance created by the massive tsunamis would have destroyed up to half of the life in the earth's oceans, according to most estimates. The impact on the earth's crust would have resulted in massive earthquakes and volcanic eruptions around the world. Global destruction and loss of much of life on earth in one day.
And if that isnt bad enough, think of the scenario resulting from the collision of the Indian sub-continent with Asia. The impact was so powerful it buckled up the edge of Asia and created the Himalayan mountain range. Earth has been through many global catastrophies that were never recorded by humans. Were humans there to witness those events? The evidence that they occured is indisputable.