The ground under Inchon, South Korea — measured by the Global Seismographic Network (IRIS/USGS) station IU INCN and redrawn here every 15 minutes. A thin band means a quiet ground; a tall spike is a passing earthquake, near or on the other side of the planet.
| Mag | Where | When | Distance |
|---|---|---|---|
| M5.5 | 5 km ESE of Asahi, Japan | 1970-01-01 00:00 UTC | 1,272 km |
| M5.3 | 44 km ESE of Miyazaki, Japan | 1970-01-01 00:00 UTC | 791 km |
| M5.2 | 0 km ENE of Yokoshiba, Japan | 1970-01-01 00:00 UTC | 1,254 km |
| M5.1 | 103 km ENE of Miyako, Japan | 1970-01-01 00:00 UTC | 1,454 km |
| M5.1 | 72 km ENE of Noda, Japan | 1970-01-01 00:00 UTC | 1,415 km |
| M4.9 | 3 km WSW of Shibayama, Japan | 1970-01-01 00:00 UTC | 1,245 km |
| M4.8 | 109 km S of Koshima, Japan | 1970-01-01 00:00 UTC | 988 km |
| M4.8 | 54 km E of Tomioka, Japan | 1970-01-01 00:00 UTC | 1,324 km |
| M4.7 | 76 km NNE of Yonakuni, Japan | 1970-01-01 00:00 UTC | 1,412 km |
| M4.7 | Izu Islands, Japan region | 1970-01-01 00:00 UTC | 1,488 km |
| Mag | Where | When | Distance |
|---|---|---|---|
| M7.7 | 12 km WSW of Pitaloza Arriba, Panama | 1970-01-01 00:00 UTC | 14,252 km |
| M7.0 | 191 km ENE of Nagqu, China | 1970-01-01 00:00 UTC | 3,032 km |
| M6.9 | 76 km NE of Ozernovskiy, Russia | 1970-01-01 00:00 UTC | 2,875 km |
| M6.9 | 197 km WNW of Port-Olry, Vanuatu | 1970-01-01 00:00 UTC | 7,026 km |
| M6.8 | central Mid-Atlantic Ridge | 1970-01-01 00:00 UTC | 14,623 km |
| M6.7 | central Mid-Atlantic Ridge | 1970-01-01 00:00 UTC | 14,598 km |
Waves from a large earthquake reach this station minutes later — up to about 20 minutes from the far side of the Earth. Look for a spike in the helicorder at that time.