The ground under Guam, Guam — measured by the Global Seismographic Network (IRIS/USGS) station IU GUMO 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 |
|---|---|---|---|
| M5.4 | 193 km WSW of Merizo Village, Guam | 1970-01-01 00:00 UTC | 228 km |
| M5.3 | 41 km NNE of Yigo Village, Guam | 1970-01-01 00:00 UTC | 38 km |
| M5.1 | Volcano Islands, Japan region | 1970-01-01 00:00 UTC | 1,030 km |
| M5.0 | 183 km ENE of Saipan, Northern Mariana Islands | 1970-01-01 00:00 UTC | 364 km |
| M5.0 | Pagan region, Northern Mariana Islands | 1970-01-01 00:00 UTC | 533 km |
| M4.9 | Volcano Islands, Japan region | 1970-01-01 00:00 UTC | 1,035 km |
| M4.9 | 119 km SSW of Merizo Village, Guam | 1970-01-01 00:00 UTC | 162 km |
| M4.9 | Pagan region, Northern Mariana Islands | 1970-01-01 00:00 UTC | 588 km |
| M4.8 | State of Yap, Federated States of Micronesia | 1970-01-01 00:00 UTC | 761 km |
| M4.7 | 221 km NNE of Colonia, Micronesia | 1970-01-01 00:00 UTC | 680 km |
| Mag | Where | When | Distance |
|---|---|---|---|
| M7.7 | 12 km WSW of Pitaloza Arriba, Panama | 1970-01-01 00:00 UTC | 14,454 km |
| M7.0 | 191 km ENE of Nagqu, China | 1970-01-01 00:00 UTC | 5,571 km |
| M6.9 | 76 km NE of Ozernovskiy, Russia | 1970-01-01 00:00 UTC | 4,410 km |
| M6.9 | 197 km WNW of Port-Olry, Vanuatu | 1970-01-01 00:00 UTC | 3,826 km |
| M6.8 | central Mid-Atlantic Ridge | 1970-01-01 00:00 UTC | 17,749 km |
| M6.7 | central Mid-Atlantic Ridge | 1970-01-01 00:00 UTC | 17,741 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.