# Moderate mag. 4.0 earthquake - Santiago Tapextla, Oaxaca, 36 km south of Ometepec, Guerrero, Mexico, on Monday, Sep 13, 2021 8:14 pm (GMT -5) - writeAge(1631582084)

Quakes around its antipode during the following 3 days
Check different time intervals: 24 hours | 2 days
Date & time: 14 Sep 2021 01:14:44 UTC -
Local time at epicenter: Monday, Sep 13, 2021 8:14 pm (GMT -5)
Magnitude: 4
Depth: 10 km
Epicenter latitude / longitude: 16.37°N / 98.44°W (Santiago Tapextla, Oaxaca, Mexico)
Antipode latitude / longitude: 16.37°S / 81.56°E
Primary data source: SSN (Servicio Sismológico Nacional)
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## Quakes within 30 degrees from seismic antipode up to 3 days after the quake

The area around the antipode is marked with the big circle on the map.
The total number of quakes that occurred within 3 days around the antipode of the quake was 12. This is compared to the average number of 10.7 quakes during preceding intervals of 3 days with a standard deviation (σ) of 8.5, calculated by analzing all 100 preceding intervals of 3 days for the same region.
Interpretation:
Note: At a magnitude of 4.0, it is unlikely that this quake could affect areas around its antipode. If an increase or decrease of quake is detected, it is likely caused by other factors.
There is no significant variation in the number of quakes that occurred around the antipode within 3 days.
 Mag class Total # Average σ Observed deviation 6+ 0 0 0.2 -0 (-0.2σ) 5+ 1 0.6 0.9 0.4 (0.4σ) 4+ 2 3 2.8 -1 (-0.4σ) 3+ 9 7 6.1 2 (0.3σ) Total 12 10.7 8.5 1.3 (0.2σ)
Explanation:
BLACK = Number of quakes within normal statistical range
RED = Significantly lower than normal number of quakes
GREEN = Significantly higher than normal number of quakes

## List of quakes

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Showing quakes magnitude 3.0 or higher (total: 12).
 Date and time MagDepth Location Details 14 Sep 2021 07:41:32 GMT(6 hours after quake) 3.210 km Southern Sumatra, Indonesia [Show on map] More 14 Sep 2021 09:14:35 GMT(8 hours after quake) 4.110 km Java, Indonesia [Show on map] More 14 Sep 2021 18:34:14 GMT(17 hours after quake) 3.520 km Southern Sumatra, Indonesia [Show on map] More 14 Sep 2021 20:13:57 GMT(19 hours after quake) 5.648 km Indonesia: Off West Coast of Northern Sumatra [Show on map] More 15 Sep 2021 07:54:31 GMT(1 day 7 hours after quake) 4.7112 km Mid Indian Ridge [Show on map] More 15 Sep 2021 08:12:37 GMT(1 day 7 hours after quake) 3.310 km Northern Sumatra, Indonesia [Show on map] More 15 Sep 2021 11:31:27 GMT(1 day 10 hours after quake) 3.4167 km Northern Sumatra, Indonesia [Show on map] More 15 Sep 2021 16:09:21 GMT(1 day 15 hours after quake) 3.821 km Java, Indonesia [Show on map] More 15 Sep 2021 16:17:00 GMT(1 day 15 hours after quake) 3.527 km Southern Sumatra, Indonesia [Show on map] More 15 Sep 2021 16:35:20 GMT(1 day 15 hours after quake) 3.410 km Southern Sumatra, Indonesia [Show on map] More 16 Sep 2021 16:45:54 GMT(3 days after quake) 3.933 km Northern Sumatra, Indonesia [Show on map] More 16 Sep 2021 23:23:18 GMT(3 days after quake) 3.912 km Southern Sumatra, Indonesia [Show on map] More
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