Earthquake with magnitude of ML 1.1 on date 23-09-2021 and time 16:54:31 (Italy) in region 9 km NE Monteverdi Marittimo (PI)

A magnitude ML 1.1 earthquake occured in region: 9 km NE Monteverdi Marittimo (PI), on

  • 23-09-2021 14:54:31 (UTC)
  • 23-09-2021 16:54:31 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.245, 10.769 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
Monteverdi Marittimo PI 9 758 758
Pomarance PI 11 5897 6655
Castelnuovo di Val di Cecina PI 12 2231 8886
Monterotondo Marittimo GR 13 1371 10257
Guardistallo PI 13 1234 11491
Casale Marittimo PI 14 1122 12613
Bibbona LI 14 3175 15788
Montescudaio PI 15 2144 17932
Castagneto Carducci LI 16 9010 26942
Sassetta LI 16 514 27456
Montecatini Val di Cecina PI 17 1749 29205
Volterra PI 19 10519 39724
Riparbella PI 19 1603 41327
Suvereto LI 20 3072 44399

Municipalities with at least 50000 inhabitants

An earthquake occurred to
46 Km W of Siena (53903 inhabitants)
51 Km SE of Livorno (159219 inhabitants)
60 Km SE of Pisa (89158 inhabitants)
61 Km NW of Grosseto (82087 inhabitants)
66 Km SW of Scandicci (50609 inhabitants)
70 Km SE of Lucca (89046 inhabitants)
70 Km SW of Firenze (382808 inhabitants)
76 Km SW of Prato (191150 inhabitants)
78 Km S of Pistoia (90315 inhabitants)
81 Km SE of Viareggio (62467 inhabitants)
93 Km W of Arezzo (99543 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 2021-09-23
14:54:31
43.2448 10.7688 7 2021-09-23
15:00:53
Sala Sismica INGV-Roma 95788881
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2021-09-23 14:54:31 ± 0.09
Latitude 43.2448 ± 0.0054
Longitude 10.7688 ± 0.0074
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 95788881

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 546
Semi-minor axis of confidence ellipse (meter) 499
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 101
Circular confidence region, given by single value of horizontal uncertainty (meter) 550
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 51
Number of associated phases, regardless of their use for origin computation 17
Number of defining phases 17
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) 0.08544
Epicentral distance of station farthest from the epicenter (degree) 0.70327
Number of stations at which the event was observed 11
Number of stations from which data was used for origin computation 11
Magnitude information

ML:1.1

Field Value
Value 1.1
Uncertainty 0.4
Num. used stations 8
Type of magnitude ML
Reference to an origin 95788881
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2021-09-23 15:00:53
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.CRMI.HNN. 2021-09-23T14:54:51.23 0.3 undecidable manual S 15 0.5711 50 -0.18 67
IV.OSSC.HHZ. 2021-09-23T14:54:47.57 0.6 undecidable manual S 51 0.4443 50 -0.09 47
IV.CASP.HHZ. 2021-09-23T14:54:47.46 0.3 undecidable manual S 171 0.4596 50 -0.63 61
Z3.A317A.HHE. 2021-09-23T14:54:45.41 0.1 undecidable manual P 254 0.7033 50 0.29 85
IV.CELB.HHE. 2021-09-23T14:54:44.05 0.1 undecidable manual P 220 0.6439 50 -0.06 91
IV.CRMI.HNN. 2021-09-23T14:54:43.35 0.1 undecidable manual P 15 0.5711 50 0.48 84
IV.FIR.HHZ. 2021-09-23T14:54:43.63 0.1 undecidable manual P 33 0.6358 50 -0.35 85
IV.FROS.CHZ. 2021-09-23T14:54:42.02 0.3 undecidable manual S 97 0.2842 103 -0.41 68
IV.CASP.HHZ. 2021-09-23T14:54:41.42 0.6 undecidable manual P 171 0.4596 50 0.47 43
IV.PII.HHZ. 2021-09-23T14:54:41.61 0.1 undecidable manual P 340 0.509 50 -0.19 91
IV.CSNT.HHE. 2021-09-23T14:54:40.79 0.1 undecidable manual P 59 0.4425 50 0.13 93
IV.OSSC.HHZ. 2021-09-23T14:54:40.84 0.1 undecidable manual P 51 0.4443 50 0.14 93
IV.TRIF.CHZ. 2021-09-23T14:54:37.84 0.6 undecidable manual S 143 0.1628 112 -0.11 49
IV.FROS.CHZ. 2021-09-23T14:54:37.88 0.1 undecidable manual P 97 0.2842 103 0.19 95
IV.TRIF.CHZ. 2021-09-23T14:54:35.42 0.1 negative manual P 143 0.1628 112 0.33 94
IV.MAGO.CHZ. 2021-09-23T14:54:34.92 0.3 undecidable manual S 289 0.0854 128 -0.43 70
IV.MAGO.CHZ. 2021-09-23T14:54:33.71 0.1 negative manual P 289 0.0854 128 0.11 100
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
IV.MAGO.CHE. ML:0 0.001542803 0.1024 AML other m 2021-09-23T14:54:34.99
IV.MAGO.CHN. ML:0 0.00179315 0.1152 AML other m 2021-09-23T14:54:35.01
IV.TRIF.CHN. ML:1.3 0.000183 0.52 AML other m 2021-09-23T14:54:37.73
IV.TRIF.CHE. ML:1.3 0.000178 0.66 AML other m 2021-09-23T14:54:38.02
IV.FROS.CHE. ML:0 3.26053285E-5 0.0896 AML other m 2021-09-23T14:54:43.61
IV.FROS.CHN. ML:0 3.2306535E-5 0.128 AML other m 2021-09-23T14:54:43.67
IV.CASP.HHE. ML:0 1.307442E-5 1.2672 AML other m 2021-09-23T14:54:48.13
IV.CASP.HHN. ML:0 1.215317E-5 0.4736 AML other m 2021-09-23T14:54:48.13
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