The ground under Santorini, Greece — measured by the GEOFON network (GFZ Potsdam) station GE THERA 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 |
|---|---|---|---|
| M5.7 | 61 km WNW of Leni, Italy | 1970-01-01 00:00 UTC | 1,031 km |
| M5.2 | 50 km WNW of Malfa, Italy | 1970-01-01 00:00 UTC | 1,019 km |
| M5.1 | 21 km ESE of Feke, Turkey | 1970-01-01 00:00 UTC | 957 km |
| M4.9 | 81 km NNW of Malfa, Italy | 1970-01-01 00:00 UTC | 1,026 km |
| M4.9 | 53 km WNW of Leni, Italy | 1970-01-01 00:00 UTC | 1,023 km |
| M4.9 | 17 km SE of Ambelókipoi, Greece | 1970-01-01 00:00 UTC | 421 km |
| M4.7 | 22 km E of Feke, Turkey | 1970-01-01 00:00 UTC | 961 km |
| M4.7 | 22 km E of Feke, Turkey | 1970-01-01 00:00 UTC | 961 km |
| M4.7 | 52 km WNW of Malfa, Italy | 1970-01-01 00:00 UTC | 1,020 km |
| M4.6 | 27 km WSW of Palaióchora, Greece | 1970-01-01 00:00 UTC | 232 km |
| Mag | Where | When | Distance |
|---|---|---|---|
| M7.7 | 12 km WSW of Pitaloza Arriba, Panama | 1970-01-01 00:00 UTC | 10,934 km |
| M7.0 | 191 km ENE of Nagqu, China | 1970-01-01 00:00 UTC | 6,152 km |
| M6.9 | 76 km NE of Ozernovskiy, Russia | 1970-01-01 00:00 UTC | 9,135 km |
| M6.9 | 197 km WNW of Port-Olry, Vanuatu | 1970-01-01 00:00 UTC | 15,344 km |
| M6.8 | central Mid-Atlantic Ridge | 1970-01-01 00:00 UTC | 6,174 km |
| M6.7 | central Mid-Atlantic Ridge | 1970-01-01 00:00 UTC | 6,161 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.