# Moderate mag. 4.0 earthquake - Provincia de Caylloma, 91 km northwest of Arequipa, Peru, on Friday, Oct 22, 2021 11:20 pm (GMT -5) - writeAge(1634962841)

Quakes around its antipode during the following 3 days
Check different time intervals: 24 hours | 2 days
Date & time: 23 Oct 2021 04:20:41 UTC -
Local time at epicenter: Friday, Oct 22, 2021 11:20 pm (GMT -5)
Magnitude: 4
Depth: 11 km
Epicenter latitude / longitude: 15.7°S / 71.98°W (Provincia de Caylloma, Arequipa, Peru)
Antipode latitude / longitude: 15.7°N / 108.02°E (Vietnam)
Primary data source: EMSC (European-Mediterranean Seismological Centre)
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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 9. This is compared to the average number of 0 quakes during preceding intervals of 3 days with a standard deviation (σ) of 0.9, 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 a weak increase in detected quakes around the antipode during the following 3 days.
 Mag class Total # Average σ Observed deviation 6+ 0 0 0 n/a 5+ 0 0 0 n/a 4+ 2 0 0.2 2 (9.9σ) 3+ 7 0 0.7 7 (9.9σ) Total 9 0 0.9 9 (9.9σ)
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

Showing quakes magnitude 3.0 or higher (total: 9).
 Date and time MagDepth Location Details 25 Oct 2021 20:43:52 GMT(3 days after quake) 3.210 km Indonesia: Ceram Sea [Show on map] More 25 Oct 2021 21:30:23 GMT(3 days after quake) 3.414 km Philippines: PHILIPPINE ISLANDS REGION [Show on map] More 25 Oct 2021 22:12:00 GMT(3 days after quake) 3.31 km Philippines: 035 Km N 83° E of Palanan (Isabela) [Show on map] More 25 Oct 2021 22:18:46 GMT(3 days after quake) 3.511 km Indonesia: Minahassa Peninsula, Sulawesi [Show on map] More 25 Oct 2021 22:31:48 GMT(3 days after quake) 3.018 km Japan: SE OFF OSUMI PEN [Show on map] More 25 Oct 2021 23:19:41 GMT(3 days after quake) 3.210 km Java, Indonesia [Show on map] More 25 Oct 2021 23:31:39 GMT(3 days after quake) 4.747 km Off West Coast of Northern Sumatra [Show on map] More 25 Oct 2021 23:48:31 GMT(3 days after quake) 4.410 km 170km SSW of Berhampur, Odisha, India [Show on map] More 25 Oct 2021 23:48:50 GMT(3 days after quake) 3.021 km Indonesia: Ceram Sea [Show on map] More
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