Earthquake with magnitude of ML 1.1 on date 18-10-2021 and time 13:41:55 (UTC) in region 1 km NW Marradi (FI)

A magnitude ML 1.1 earthquake occured in region: 1 km NW Marradi (FI), on

  • 18-10-2021 13:41:55 (UTC)
  • 18-10-2021 15:41:55 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 44.083, 11.602 at 7 km depth.

The earthquake was located by: Sala Sismica INGV-Roma.

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.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Marradi FI 1 3139 3139
Palazzuolo sul Senio FI 5 1154 4293
Tredozio FC 11 1212 5505
Portico e San Benedetto FC 16 756 6261
Casola Valsenio RA 16 2617 8878
Castel del Rio BO 17 1246 10124
San Godenzo FI 17 1167 11291
Modigliana FC 17 4560 15851
Firenzuola FI 18 4726 20577
Premilcuore FC 18 799 21376
Rocca San Casciano FC 19 1910 23286
Vicchio FI 20 8044 31330
Fontanelice BO 20 1943 33273

Municipalities with at least 50000 inhabitants

An earthquake occurred to
32 Km SW of Imola (69797 inhabitants)
32 Km SW of Faenza (58541 inhabitants)
38 Km W of Forlì (117913 inhabitants)
44 Km NE of Firenze (382808 inhabitants)
46 Km E of Prato (191150 inhabitants)
49 Km NE of Scandicci (50609 inhabitants)
50 Km SE of Bologna (386663 inhabitants)
52 Km W of Cesena (96758 inhabitants)
57 Km E of Pistoia (90315 inhabitants)
61 Km SW of Ravenna (159116 inhabitants)
72 Km NW of Arezzo (99543 inhabitants)
77 Km W of Rimini (147750 inhabitants)
83 Km SE of Modena (184973 inhabitants)
84 Km S of Ferrara (133155 inhabitants)
88 Km N of Siena (53903 inhabitants)
92 Km E of Lucca (89046 inhabitants)
96 Km SE of Carpi (70699 inhabitants)
Recent and historical seismicity
Seismic hazard
Shakemap
Felt maps
Preliminary map of the earthquake effects from the web questionnaire

Preliminary map of the earthquake effects from the web questionnaire

This map shows the distribution of the effects of the earthquake on the territory in terms of the MCS (Mercalli-Cancani-Sieberg) intensity scale. The intensities are determined using the data provided in the questionnaire (http://www.haisentitoilterremoto.it/) that are analysed using robust statistical techniques since they are not verified individually. Specifically, the assignment of MCS intensities greater or equal the VI degree of the MCS scale require opportune in situ verification by professional experts. The purple start shows the epicenter. This map is prepared every so often that the population fill in new questionnaires. The number of questionnaires used to determine the map and the date and time of the last adjournment are shown in the upper right part of the panel.
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
Reviewed
Rev100
ML 1.1 2021-10-18
13:41:55
44.083 11.6015 7 2021-10-18
13:53:00
Sala Sismica INGV-Roma 96728491
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-10-18 13:41:55 ± 0.15
Latitude 44.0830 ± 0.0072
Longitude 11.6015 ± 0.0075
Depth (km) 7 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 96728491

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 702
Semi-minor axis of confidence ellipse (meter) 406
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 206
Circular confidence region, given by single value of horizontal uncertainty (meter) 700
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 89
Number of associated phases, regardless of their use for origin computation 19
Number of defining phases 16
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.3
Epicentral distance of station closest to the epicenter (degree) 0
Epicentral distance of station farthest from the epicenter (degree) 0.5279
Number of stations at which the event was observed 12
Number of stations from which data was used for origin computation 9
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.2
Num. used stations 12
Type of magnitude ML
Reference to an origin 96728491
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-10-18 13:53:00
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.FDMO.HHZ. 2021-10-18T13:42:44.13 3.0 undecidable manual S -0.15 0
IV.CRE.HHZ. 2021-10-18T13:42:14.83 0.6 undecidable manual S 151 0.5279 50 0.67 40
IV.APEC.HHZ. 2021-10-18T13:42:12.02 3.0 positive manual P 0.46 0
IV.ASQU.HHZ. 2021-10-18T13:42:07.87 0.6 undecidable manual S 155 0.3166 102 0.24 48
IV.MOCL.EHZ. 2021-10-18T13:42:07.84 0.6 undecidable manual S 256 0.3121 102 0.38 46
IV.CSNT.HHZ. 2021-10-18T13:42:05.99 3.0 positive manual P -2.77 0
IV.RUFI.EHZ. 2021-10-18T13:42:05.54 0.6 undecidable manual S 195 0.2536 104 0.27 48
IV.CRE.HHZ. 2021-10-18T13:42:05.74 1.0 negative manual P 151 0.5279 50 -0.4 22
IV.VISG.HHZ. 2021-10-18T13:42:02.09 0.6 undecidable manual S 311 0.1601 112 0.26 49
IV.ASQU.HHZ. 2021-10-18T13:42:02.01 0.1 positive manual P 155 0.3166 102 -0.36 93
IV.SEI.HHZ. 2021-10-18T13:42:02.84 0.6 undecidable manual S 261 0.1772 110 0.4 47
IV.MOCL.EHZ. 2021-10-18T13:42:01.91 0.3 positive manual P 256 0.3121 102 -0.37 70
IV.RUFI.EHZ. 2021-10-18T13:42:00.89 0.6 positive manual P 195 0.2536 104 -0.12 49
IV.SFI.HNZ. 2021-10-18T13:42:00.77 0.1 undecidable manual P 135 0.2509 104 -0.18 98
IV.SEI.HHZ. 2021-10-18T13:41:59.24 0.1 positive manual P 261 0.1772 110 -0.14 100
IV.LMD.HHZ. 2021-10-18T13:41:59.59 0.6 undecidable manual S 94 0.0764 130 0.56 46
IV.BRIS.HHZ. 2021-10-18T13:41:59.97 0.3 positive manual P 40 0.1844 109 0.44 70
IV.VISG.HHZ. 2021-10-18T13:41:58.72 0.3 positive manual P 311 0.1601 112 -0.3 73
IV.LMD.HHZ. 2021-10-18T13:41:57.10 0.1 positive manual P 94 0.0764 130 -0.3 98
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.VISG.HHN. ML:1 9.535E-5 0.98 AML other m 2021-10-18T13:42:02.69
IV.ASQU.HHN. ML:0.9 3.176547E-5 0.2368 AML other m 2021-10-18T13:42:08.52
IV.VISG.HHE. ML:0.9 6.87E-5 0.2 AML other m 2021-10-18T13:42:03.16
IV.SEI.HHN. ML:1.6 0.0003505 0.5 AML other m 2021-10-18T13:42:03.42
IV.SEI.HHE. ML:1.4 0.000224 1.4 AML other m 2021-10-18T13:42:03.06
IV.BRIS.HHE. ML:0 0.00010405 0.38 AML other m 2021-10-18T13:42:06.19
IV.MOCL.EHN. ML:1.2 6.0E-5 1.06 AML other m 2021-10-18T13:42:07.93
IV.ASQU.HHE. ML:1 4.275E-5 1.34 AML other m 2021-10-18T13:42:08.14
IV.MOCL.EHE. ML:1.1 4.895E-5 0.22 AML other m 2021-10-18T13:42:08.40
IV.BRIS.HHN. ML:0 0.0001325 0.36 AML other m 2021-10-18T13:42:10.70
IV.CRE.HHE. ML:0.7 1.147735E-5 0.3008 AML other m 2021-10-18T13:42:15.11
IV.CRE.HHN. ML:0.8 1.6933115E-5 0.1984 AML other m 2021-10-18T13:42:15.34
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