Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of ML 0.9 on date 18-08-2021 and time 02:48:08 (Italy) in region 9 km SE Castelsantangelo sul Nera (MC)

A magnitude ML 0.9 earthquake occured in region: 9 km SE Castelsantangelo sul Nera (MC), on

  • 18-08-2021 00:48:08 (UTC)
  • 18-08-2021 02:48:08 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.8250, 13.2040 at 9 km depth.

The earthquake was located by: Bollettino Sismico Italiano INGV.

Search earthquakes: Any within 30 km radius

The values of hypocentral coordinates and magnitude may be revised at a later time as more information becomes available.

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Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Castelsantangelo sul Nera MC 9 281 281
Arquata del Tronto AP 10 1178 1459
Norcia PG 10 4957 6416
Montegallo AP 11 523 6939
Montemonaco AP 13 604 7543
Ussita MC 14 444 7987
Preci PG 15 724 8711
Accumoli RI 15 667 9378
Visso MC 15 1107 10485
Montefortino FM 17 1178 11663
Acquasanta Terme AP 18 2916 14579
Bolognola MC 19 142 14721
Cascia PG 20 3217 17938

Municipalities with at least 50000 inhabitants

An earthquake occurred to
43 Km E of Foligno (57155 inhabitants)
45 Km W of Teramo (54892 inhabitants)
54 Km NE of Terni (111501 inhabitants)
55 Km N of L'Aquila (69753 inhabitants)
73 Km E of Perugia (166134 inhabitants)
85 Km W of Montesilvano (53738 inhabitants)
92 Km S of Ancona (100861 inhabitants)
92 Km W of Pescara (121014 inhabitants)
95 Km NW of Chieti (51815 inhabitants)
100 Km NE of Guidonia Montecelio (88673 inhabitants)
Recent and historical seismicity
Seismic hazard
Shakemap
Felt maps
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
Bulletin
Rev1000 		ML 0.9 2021-08-18
00:48:08		 42.8248 13.2043 9 2021-12-29
11:12:24		 Bollettino Sismico Italiano INGV 94919411
Reviewed
Rev100 		ML 0.9 2021-08-18
00:48:08		 42.8198 13.2223 8 2021-08-18
00:52:27		 Sala Sismica INGV-Roma 94316111
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-08-18 00:48:08 ± 0.07
Latitude 42.8248 ± 0.0036
Longitude 13.2043 ± 0.0049
Depth (km) 9 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 94919411

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 425
Semi-minor axis of confidence ellipse (meter) 171
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 251
Circular confidence region, given by single value of horizontal uncertainty (meter) 420.0
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 66
Number of associated phases, regardless of their use for origin computation 23
Number of defining phases 23
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.22
Epicentral distance of station closest to the epicenter (degree) 0.06655
Epicentral distance of station farthest from the epicenter (degree) 0.35613
Number of stations at which the event was observed 14
Number of stations from which data was used for origin computation 14
Magnitudes information

ML:0.9

Field Value
Value 0.9
Uncertainty 0.3
Num. used stations 6
Type of magnitude ML
Reference to an origin 94919411
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2021-09-01 14:18:48

ML:0.9

Field Value
Value 0.9
Uncertainty 0.2
Num. used stations 8
Type of magnitude ML
Reference to an origin 94316111
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-08-18 00:52:27
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
IV.TERO.HHZ. 2021-08-18T00:48:22.00 0.3 undecidable manual S 124 39.5271 50 -0.14 69
IV.CESI.HHE. 2021-08-18T00:48:20.30 0.6 undecidable manual S 309 31.4463 50 0.31 45
IV.CSP1.EHZ. 2021-08-18T00:48:19.16 0.3 undecidable manual S 0 29.6481 107 -0.27 68
IV.GUMA.HHZ. 2021-08-18T00:48:19.44 0.6 undecidable manual S 22 28.4493 108 0.4 44
IV.FDMO.HHZ. 2021-08-18T00:48:18.29 0.3 undecidable manual S 338 25.3524 110 0.27 69
IV.TERO.HHZ. 2021-08-18T00:48:16.07 0.6 undecidable manual P 124 39.5271 50 -0.38 44
IV.MTRA.HNZ. 2021-08-18T00:48:15.44 0.6 undecidable manual S 116 17.3715 118 -0.05 49
IV.GUMA.HHZ. 2021-08-18T00:48:14.96 0.1 undecidable manual P 22 28.4493 108 0.29 91
IV.GAVE.EHN. 2021-08-18T00:48:14.59 0.3 undecidable manual P 240 29.2485 107 -0.23 69
IV.FDMO.HHZ. 2021-08-18T00:48:14.24 0.1 undecidable manual P 338 25.3524 110 0.17 94
IV.SMA1.EHZ. 2021-08-18T00:48:14.28 0.3 undecidable manual P 154 24.0537 111 0.44 67
IV.MF5.EHZ. 2021-08-18T00:48:14.83 0.3 undecidable manual P 49 27.5502 108 0.34 68
IV.CSP1.EHZ. 2021-08-18T00:48:14.73 0.3 undecidable manual P 0 29.6481 107 -0.16 70
IV.CESI.HHE. 2021-08-18T00:48:14.91 0.1 undecidable manual P 309 31.4463 50 -0.3 90
IV.LNSS.HNZ. 2021-08-18T00:48:14.65 0.1 undecidable manual P 209 28.0497 108 0.06 95
IV.T1299.HNZ. 2021-08-18T00:48:13.78 0.6 undecidable manual P 163 22.0668 112 0.31 46
IV.MC2.EHZ. 2021-08-18T00:48:13.18 0.3 undecidable manual S 353 9.6792 133 -0.11 73
IV.MMO1.EHZ. 2021-08-18T00:48:13.80 0.3 undecidable manual S 50 12.9759 125 -0.37 69
IV.NRCA.HHZ. 2021-08-18T00:48:12.58 0.3 undecidable manual S 277 7.3815 141 -0.17 72
IV.MTRA.HNZ. 2021-08-18T00:48:12.63 0.1 undecidable manual P 116 17.3715 118 0.01 98
IV.MMO1.EHZ. 2021-08-18T00:48:11.60 0.3 undecidable manual P 50 12.9759 125 -0.25 71
IV.NRCA.HHZ. 2021-08-18T00:48:11.03 0.1 undecidable manual P 277 7.3815 141 0 100
IV.MC2.EHZ. 2021-08-18T00:48:11.35 0.3 undecidable manual P 353 9.6792 133 0 75
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.NRCA.HHN. ML:0.9 0.000123 0.12 AML other m 2021-08-18T00:48:12.76
IV.NRCA.HHE. ML:0.9 0.00013550000000000001 0.74 AML other m 2021-08-18T00:48:12.98
IV.FDMO.HHE. ML:0.6 0.000022550675 1.94 AML other m 2021-08-18T00:48:19.27
IV.FDMO.HHN. ML:0.2 0.0000101713295 1.9 AML other m 2021-08-18T00:48:19.15
IV.CSP1.EHN. ML:1.2 0.000067803315 3.34 AML other m 2021-08-18T00:48:19.96
IV.CSP1.EHE. ML:1.0 0.00005259619 5.56 AML other m 2021-08-18T00:48:20.76
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download