Earthquake with magnitude of ML 0.8 on date 20-10-2021 and time 17:11:34 (UTC) in region 5 km N Vecchiano (PI)

A magnitude ML 0.8 earthquake occured in region: 5 km N Vecchiano (PI), on

  • 20-10-2021 17:11:34 (UTC)
  • 20-10-2021 19:11:34 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.824, 10.395 at 10 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
Vecchiano PI 5 12189 12189
Massarosa LU 7 22471 34660
San Giuliano Terme PI 8 31399 66059
Lucca LU 9 89046 155105
Pisa PI 12 89158 244263
Viareggio LU 13 62467 306730
Calci PI 15 6426 313156
Camaiore LU 15 32513 345669
Capannori LU 15 46252 391921
Pescaglia LU 16 3526 395447
Porcari LU 18 8845 404292
Buti PI 19 5791 410083

Municipalities with at least 50000 inhabitants

An earthquake occurred to
9 Km W of Lucca (89046 inhabitants)
12 Km N of Pisa (89158 inhabitants)
13 Km E of Viareggio (62467 inhabitants)
31 Km N of Livorno (159219 inhabitants)
31 Km SE of Massa (69479 inhabitants)
37 Km SE of Carrara (63133 inhabitants)
44 Km W of Pistoia (90315 inhabitants)
55 Km SE of La Spezia (93959 inhabitants)
57 Km W of Prato (191150 inhabitants)
64 Km W of Scandicci (50609 inhabitants)
69 Km W of Firenze (382808 inhabitants)
94 Km NW of Siena (53903 inhabitants)
99 Km S of Reggio nell'Emilia (171345 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 0.8 2021-10-20
17:11:34
43.8245 10.3952 10 2021-10-20
17:22:40
Sala Sismica INGV-Roma 96805611
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-10-20 17:11:34 ± 0.3
Latitude 43.8245 ± 0.0063
Longitude 10.3952 ± 0.0262
Depth (km) 10 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 100 -> SURVEY-INGV
Event type earthquake
Origin ID 96805611

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 2142
Semi-minor axis of confidence ellipse (meter) 623
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 263
Circular confidence region, given by single value of horizontal uncertainty (meter) 2140
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 239
Number of associated phases, regardless of their use for origin computation 10
Number of defining phases 10
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.25
Epicentral distance of station closest to the epicenter (degree) 0.11242
Epicentral distance of station farthest from the epicenter (degree) 0.34084
Number of stations at which the event was observed 5
Number of stations from which data was used for origin computation 5
Magnitude information

ML:0.8

Field Value
Value 0.8
Uncertainty 0.2
Num. used stations 8
Type of magnitude ML
Reference to an origin 96805611
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-10-20 17:22:40
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
GU.POPM.HHZ. 2021-10-20T17:11:47.78 0.3 undecidable manual S 50 0.3408 50 0.08 72
IV.BDI.HHE. 2021-10-20T17:11:45.76 0.6 undecidable manual S 31 0.2788 50 -0.08 49
GU.CARD.HHZ. 2021-10-20T17:11:43.16 0.6 undecidable manual S 17 0.2113 113 -0.55 44
GU.POPM.HHZ. 2021-10-20T17:11:42.31 0.1 undecidable manual P 50 0.3408 50 0.03 97
IV.BDI.HHE. 2021-10-20T17:11:41.15 0.1 undecidable manual P 31 0.2788 50 -0.06 98
GU.MAIM.HHZ. 2021-10-20T17:11:40.62 0.6 undecidable manual S 38 0.1124 128 0.2 49
IV.PII.HHZ. 2021-10-20T17:11:40.88 0.6 undecidable manual S 138 0.1385 123 -0.37 47
GU.CARD.HHZ. 2021-10-20T17:11:39.92 0.1 undecidable manual P 17 0.2113 113 -0.06 99
IV.PII.HHZ. 2021-10-20T17:11:38.63 0.1 negative manual P 138 0.1385 123 0.07 100
GU.MAIM.HHZ. 2021-10-20T17:11:38.53 0.3 negative manual P 38 0.1124 128 0.45 70
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.PII.HHN. ML:1.2 0.0001408 0.26 AML other m 2021-10-20T17:11:41.23
IV.PII.HHE. ML:1.1 0.00013 0.26 AML other m 2021-10-20T17:11:41.37
GU.POPM.HHN. ML:0.9 3.02E-5 1.56 AML other m 2021-10-20T17:11:49.05
GU.POPM.HHE. ML:0.7 2.2375E-5 1.04 AML other m 2021-10-20T17:11:49.86
GU.MAIM.HHE. ML:0.6 3.800233E-5 0.1536 AML other m 2021-10-20T17:11:40.97
GU.MAIM.HHN. ML:0.7 5.462675E-5 0.2048 AML other m 2021-10-20T17:11:40.91
GU.CARD.HHE. ML:0.6 2.674265E-5 0.128 AML other m 2021-10-20T17:11:44.55
GU.CARD.HHN. ML:0.7 3.3640455E-5 0.1408 AML other m 2021-10-20T17:11:45.08
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