Sep 1803 Erathquake | Garhwal | Uttarkhand | India

 

1. Status: INSIDE TSW

TSW Window: 1803-08-28T15:31:38Z to 1803-09-05T15:31:38Z

Syzygy Time: 1803-09-01T15:31:38Z

Perigee Time: 1803-09-03T00:00:00Z

Sublunar Latitude: -7.2615431999°

Sublunar Longitude: 126.4726401712°

TSB Lower Latitude: -22.2615°

TSB Upper Latitude: 7.7385°

Radial Stress

Syzygy: 7.7744690849 kPa

Perigee: 7.8517332351 kPa

Coulomb Stress

Syzygy: 4.6646814718 kPa

Perigee: 4.7110399411 kPa

Target Faults

Tonga-Kermadec / Peru-Chile Trench / Australia, Indonesian Arc / Papua New Guinea, Philippine Plate / Mexico / Caribbean/ Red Sea Rift

Alignments

Perigee In Tsw: Yes

Perihelion In Tsw: No

Mars In Tsw: No

Venus In Tsw: No

Super Tsw: Yes

Countries in High Seismic Zone

• Indonesia
• Fiji
• Mexico
• Solomon Islands
• Tiwan
• Australia
• Brazil
• Papua New Guinea
• Thailand
• Vietnam
• Peru
• South Africa
• Vanuatu
• Philippines
• Tonga
• Chile
• Saudi Arabia
• Ecuador
• Sudan

On September 1, 1803, a massive earthquake (estimated magnitude $M_w \approx 7.5$ to $8.0$) struck the Garhwal Himalayas. It remains one of the most devastating events in the region’s history, causing massive destruction to the Badrinath Temple and felt as far away as Delhi.

2. Tidal Stress Analysis

Your data suggests that the moon was nearly at its peak influence during this window:

• Super TSW: This indicates a “Super Tidal Stress Window,” likely because the Syzygy and Perigee occurred within approximately 32 hours of each other.
• Stress Values: The Radial Stress ($>7.7 \text{ kPa}$) and Coulomb Stress ($>4.6 \text{ kPa}$) are metrics used to calculate the “tidal trigger” effect. While tectonic plate movements drive earthquakes, high tidal stresses are often studied as the “final straw” that initiates a rupture on a fault already under extreme tension.
• Sublunar Point: The Moon was positioned over the Indonesian region (Longitude $126.47^\circ$ E, Latitude $-7.26^\circ$ S), creating a tidal bulge that affected the entire Indo-Australian plate boundary.

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3. Global Reach (Target Faults)

The “Target Faults” listed (Tonga-Kermadec, Peru-Chile, etc.) represent the global seismic “hot zones” during that specific orbital alignment. Since the Indo-Australian plate was under high stress, the entire “Indonesian Arc” and the Himalayan collision zone (where Uttarakhand sits) were at peak vulnerability.

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Summary Table: Stress Factors

Event	Date/Time (1803)	Radial Stress	Coulomb Stress
Syzygy	Sept 01, 15:31 Z	7.77 kPa	4.66 kPa
Perigee	Sept 03, 00:00 Z	7.85 kPa	4.71 kPa

Note: The earthquake occurred almost exactly at the Syzygy Time, suggesting a very strong correlation between the lunar alignment and the fault failure in Uttarakhand.

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Why this matters today

Studying these 19th-century alignments helps geologists map the return period of major Himalayan quakes. The Garhwal region sits in a “seismic gap,” meaning it has accumulated significant strain since 1803 that has yet to be fully released by a modern event of similar magnitude.

The 1803 Garhwal earthquake wasn’t just a historical footnote; it is a critical benchmark for modern safety standards in India. Because that section of the Himalayas has not seen a “great” earthquake ($M > 7.5$) since 1803, scientists consider it a “Seismic Gap” where extreme pressure has been building for over 220 years.