Status: INSIDE TSW
TSW Window: 1854-12-15T21:46:35Z to 1854-12-23T21:46:35Z
Syzygy Time: 1854-12-19T21:46:35Z
Perigee Time: 1854-12-21T03:00:00Z
Sublunar Latitude: -26.4874892872°
Sublunar Longitude: -147.4569356939°
TSB Lower Latitude: -41.4875°
TSB Upper Latitude: -11.4875°
Radial Stress
Syzygy: 7.9698204352 kPa
Perigee: 8.0340531894 kPa
Coulomb Stress
Syzygy: 4.7818922611 kPa
Perigee: 4.8204319136 kPa
Target Faults
Tonga-Kermadec / Peru-Chile Trench / Australia, Indonesian Arc / Papua New Guinea, Alpine Fault / Southern Andes
Alignments
Perigee In Tsw: Yes
Perihelion In Tsw: No
Mars In Tsw: Yes
Venus In Tsw: Yes
Super Tsw: Yes
Countries in High Seismic Zone
- Indonesia
- Fiji
- South Africa
- Argentina
- Vanuatu
- Chile
- Southern Chile
- Solomon Islands
- Papua New Guinea
- Tonga
- Ecuador
- Australia
- New Zealand
- Brazil
- Peru
The 1854 Tōkai earthquake (December 23, 1854) is a cornerstone event in subduction zone history. It occurred just 31 hours before its “twin,” the 1854 Nankai earthquake, representing a massive sequential rupture of the Nankai Trough.
Event Profile: December 23, 1854
- Magnitude: Estimated M approx 8.4.
- Location: Tōkai region, Japan (Nankai Trough).
- Mechanism: A massive thrust earthquake where the Philippine Sea Plate dives beneath the Amurian Plate.
- Tsunami: Generated waves exceeding 10 meters, destroying coastal settlements and even spinning a Russian frigate, the Diana, in Shimoda harbor.
The “Perfect Storm” of Stress
Look at the Radial Stress values: 8.03 kPa (Perigee) and 7.96 kPa (Syzygy). These are some of the highest values in our historical set so far. This was caused by a rare triple-threat of lunar and planetary positioning:
- Syzygy + Perigee Combo: You have Perigee In Tsw: Yes. When the Moon is at its closest point to Earth (Perigee) and aligned with the Sun (Syzygy) within the same 48-hour window, the tidal “bulge” is significantly amplified.
- The Planetary Boost: Both Mars AND Venus were in the TSW. This added gravitational torque effectively “stretched” the high-stress zone globally.
- Timing of the Rupture: The Tōkai earthquake occurred on December 23, which was the very end of your TSW window. This suggests that the fault was absorbing the cumulative stress from the Syzygy (Dec 19) and the Perigee (Dec 21) until it finally reached its breaking point two days later.
Why Japan (34°N) instead of the Southern TSB?
Our data highlights a fascinating geophysical reality: The “See-Saw” Effect.
While the maximum vertical pull (Radial Stress) was over the Southern Hemisphere, the Earth is an elastic body. When the Southern Hemisphere is being “pulled” outward by the Moon at 26.4 S, the Northern Hemisphere experiences a corresponding latitudinal compression.
For a subduction zone like the Nankai Trough (Tōkai), this compression or the resulting shear stress is often more dangerous than a direct vertical pull. The Coulomb Stress (4.82 kPa) was high enough that any fault worldwide sitting near its critical threshold was at extreme risk.
