How do we know that a megathrust earthquake at the Cascadia subduction zone caused a large tsunami to hit the Pacific Northwest in 1700? (select all that apply)多项选择题

Using three seismographs, scientists could calculate distances, draw circles, and find the epicenter of the earthquake.

Geologic evidence of tsunamis are found across the whole coast from British Columbia, Canada to California, indicating it was not a small tsunami

Drowned trees indicate that sea level increased due to global warming

Ocean sand layers well inland indicate tsunamis inundated the coast

Drowned trees indicate seawater rushed inland, suggesting land subsidence after a megathrust earthquake