00:00An 8.8-magnitude earthquake just hit Russia, one of the strongest in history.
00:05But the tsunami? Much weaker than expected.
00:08Here's why that shock didn't bring the surge we all feared.
00:11The quake struck Kamchatka, a hotspot on the Pacific Ring of Fire.
00:16Tectonic plates collide here constantly.
00:18Over time, pressure builds until it suddenly snaps.
00:22This creates a megathrust earthquake.
00:24It's not just one point shaking, it's hundreds of kilometers of fault line tearing apart.
00:29But even with all that power, tsunamis aren't guaranteed.
00:32In this case, waves up to 4 meters hit the coast, serious, but nowhere near the monster
00:37waves of 2004 or 2011.
00:40Why?
00:41First, the shape of the seafloor and coastline plays a huge role in wave amplification.
00:45Second, the depth of the rupture matters.
00:49Models showed it was about 20 tons deep.
00:51Just 20 km or deeper, and the tsunami would have been drastically smaller.
00:55Most importantly, warning systems worked.
00:58Over 1.9 million people were evacuated in time.
01:01The Earth shook, but this time, human readiness saved lives.
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