Moderate mag. 4.9 earthquake - San Marcos, 39 km southwest of Ayutla de los Libres, Guerrero, Mexico, on Monday, Sep 20, 2021 4:36 am (GMT -5) -

This quake was likely an aftershock of the 7.1 quake North Pacific Ocean, 8 km south of Acapulco de Juarez, Guerrero, Mexico, Sep 7, 2021 8:47 pm (GMT -5), which had occurred 12 days earlier.
Moderate mag. 4.9 earthquake - San Marcos, 39 km southwest of Ayutla de los Libres, Guerrero, Mexico, on Monday, Sep 20, 2021 4:36 am (GMT -5)

Moderate magnitude 4.9 earthquake at 25 km depth

20 Sep 09:54 UTC: First to report: VolcanoDiscovery after 18 minutes.
20 Sep 10:00: Now using data updates from SSN
Date & time: Sep 20, 2021 09:36:33 UTC -
Local time at epicenter: Monday, Sep 20, 2021 4:36 am (GMT -5)
Magnitude: 4.9
Depth: 25.0 km
Epicenter latitude / longitude: 16.65°N / 99.25°W (San Marcos, Guerrero, Mexico)
Antipode: 16.65°S / 80.75°E
Nearby towns and cities:
3 km (2 mi) NW of Boca del Rio (pop: 492) --> See nearby quakes!
13 km (8 mi) S of Las Vigas (pop: 4,500) --> See nearby quakes!
16 km (10 mi) WSW of Florencio Villarreal (Cruz Grande) (pop: 11,800) --> See nearby quakes!
22 km (14 mi) SE of San Marcos (pop: 13,300) --> See nearby quakes!
29 km (18 mi) W of Copala (pop: 6,620) --> See nearby quakes!
39 km (24 mi) SSW of Ayutla de los Libres (pop: 15,400) --> See nearby quakes!
74 km (46 mi) ESE of Acapulco de Juarez (pop: 673,500) --> See nearby quakes!
90 km (56 mi) W of Ometepec (pop: 24,100) --> See nearby quakes!
104 km (64 mi) SSE of Chilpancingo (pop: 187,300) --> See nearby quakes!
309 km (192 mi) S of Mexico City (pop: 12,294,200) --> See nearby quakes!
Weather at epicenter at time of quake:
Overcast Clouds 24.9°C (77 F), humidity: 88%, wind: 2 m/s (3 kts) from N
Primary data source: SSN (Servicio Sismológico Nacional)
Estimated released energy: 1.4 x 1012 joules (392 megawatt hours, equivalent to 338 tons of TNT) More info
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Data for the same earthquake reported by different agencies

Info: The more agencies report about the same quake and post similar data, the more confidence you can have in the data. It takes normally up to a few hours until earthquake parameters are calculated with near-optimum precision.
Mag.DepthLocationSource
4.925 kmMexico: 22 Km Al SURESTE De SAN MARCOS, GROSSN
4.520 kmGuerrero, MexicoGFZ
4.62 kmGUERRERO, MEXICOEMSC
4.610 km7 Km SW of Cruz Grande, MexicoUSGS

User reports for this quake (7)

User reports estimate the perceived ground shaking intensity according to the MMI (Modified Mercalli Intensity) scale.
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near Cruz Grande, Florencio Villarreal, Guerrero (2.4 km ENE of epicenter) [Map] / Weak shaking (MMI III) / rattling, vibrating / 1-2 s : Se sintió cómo 3 brincos como si pasara un Trailer pesado aquí afuera en realidad fue muy rápido y por una parte pensamos que ya estábamos siscados pero en si si paso pues los vidrios de las ventanas y el balcón sonaron | One user found this interesting.  
Copala, Guerrero (30.2 km E of epicenter) [Map] / Moderate shaking (MMI V) / vibration and rolling / very short : Estaba acostada en un colchon sobre el piso, escuche la sacudida de los muebles y del espejo, sentí que estuvo medio fuerte, pero duro muy poco  
Cdmx / not felt (reported through our app)
Estado de México / not felt (reported through our app)
Yautepec Morelos México / Light shaking (MMI IV) / horizontal (sideways) swinging / 5-10 s : Me despertó el movimiento y el crujir de mi edificio  
Ciudad de México / Very weak shaking (MMI II) : Movimiento ligero de objetos colgantes  
Ixtepec, Oaxaca / Very weak shaking (MMI II) / 2-5 s : Agitación de la ventana de mi habitación y balanceo en mi habitación muy leve  
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