ISTITUTO NAZIONALE DI GEOFISICA E VULCANOLOGIA

Earthquake with magnitude of ML 2.1 on date 01-04-2018 and time 00:39:43 (Italy) in region 4 km NW Castiglione d'Orcia (SI)

A magnitude ML 2.1 earthquake occured in region: 4 km NW Castiglione d'Orcia (SI), on

  • 31-03-2018 22:39:43 (UTC)
  • 01-04-2018 00:39:43 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 43.02, 11.58 at 10 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.

Municipalities within 20 km from the epicenter

Distances are determinated based on the geographic coordintes of the (Istat).
Municipality Region Dist Inh Cum Inh
Castiglione d'Orcia SI 4 2346 2346
San Quirico d'Orcia SI 5 2662 5008
Montalcino SI 8 5093 10101
Pienza SI 10 2107 12208
Seggiano GR 11 961 13169
San Giovanni d'Asso SI 15 853 14022
Castel del Piano GR 15 4690 18712
Buonconvento SI 15 3173 21885
Arcidosso GR 17 4285 26170
Abbadia San Salvatore SI 18 6444 32614
Montepulciano SI 18 14097 46711
Trequanda SI 20 1254 47965

Municipalities with at least 50000 inhabitants

An earthquake occurred to
39 Km SE of Siena (53903 inhabitants)
48 Km NE of Grosseto (82087 inhabitants)
55 Km SW of Arezzo (99543 inhabitants)
67 Km W of Perugia (166134 inhabitants)
80 Km NW of Viterbo (67173 inhabitants)
87 Km SE of Firenze (382808 inhabitants)
88 Km SE of Scandicci (50609 inhabitants)
92 Km W of Foligno (57155 inhabitants)
Recent and historical Seismicity

These maps show the seismicity for different time windows. The earthquake locations reported in these maps are determined in quasi real-time by the personnel on duty in the seismic surveillance center of INGV in Rome. Note that the earthquake source parameters (hypocentral location and magnitude) are the best estimates obstained with the available data and they are adjourned as additional data become available. The source parameters obtained by the personnel on duty are then revised by the group in charge of the INGV Seismic Bulletin (Bollettino Sismico Italiano dell’INGV).

Earthquakes of the last three days (72 hours)

Earthquakes of the last three days (72 hours) *

This map reports the earthquake epicenters located in the past 72 hours (3 days) from the time this page has been generated. The radius of the circle representing the earthquake on the map scales with magnitude. The color depends on the time of occurrence of the earthquakes with respect to the time of generation of the map (red = 1 hour; orange = 24 hours; yellow = 72 hours). The open star shows the epicenter of the current earthquake.
Earthquakes of the last 90 days

Earthquakes of the last 90 days *

This map reports the Magnitudo ≥ 1.0 earthquake epicenters located using the data acquired by the Italian National Seismic Network and by other collaborating networks in Italy and in the neighbouring countries. The radii of the circles representing the epicenters on the map scale with magnitude. The color of each circle depends on the time of occurrence of the earthquakes with respect to the time of generation of the map (red = 1 hour; orange = 24 hours; yellow = 72 hours; blue = all other earthquakes). The open star shows the epicenter of the current earthquake.
Earthquakes since 1985

Earthquakes since 1985 *

This map reports the Magnitudo ≥ 2.5 earthquake epicenters located using the data acquired by the Italian National Seismic Network and by other collaborating networks in Italy and in the neighbouring countries. The radii of the circles representing the epicenters on the map scale with magnitude. The color of each circle depends on the time of occurrence of the earthquakes with respect to the time of generation of the map (red = 1 hour; orange = 24 hours; yellow = 72 hours; blue = all other earthquakes). The open star shows the epicenter of the current earthquake.
Significant earthquakes since 1000 AD until 2006

Significant earthquakes since 1000 AD until 2006 *

This map shows the epicenters of the historical earthquakes catalogue CPT11 (Catalogo Parametrico dei Terremoti Italiani, 2011 version) with estimated magnitude ≥ 5.0 since 1000 AD until 2006. The epicenters are represented by squares which sides scale with the estimated earthquake magnitude. For earthquakes with magnitude ≥ 6.0, it is also shown the year of occurrence and the magnitude value. The open star shows the epicenter of the current earthquake.
Seismic hazard
Shakemap
Felt maps
The earthquake effects in MCS scale as obtained from the compiled questionnaire

The earthquake effects in MCS scale as obtained from the compiled 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
Rev 1000 ML 2.1 2018-03-31
22:39:43
43.02 11.58 10 2019-04-24
14:49:50
Bollettino Sismico Italiano INGV 66163161
Rev 100 ML 2.0 2018-03-31
22:39:43
43.02 11.58 10 2018-03-31
22:48:33
Sala Sismica INGV-Roma 55008271
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 2018-03-31 22:39:43 ± 0.13
Latitude 43.02 ± 0.01
Longitude 11.58 ± 0.01
Depth (km) 10 ± 1 (from location)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-INGV
Event type earthquake
Origin ID 66163161

Uncertainty

Field Value
Preferred uncertainty description uncertainty ellipse
Semi-major axis of confidence ellipse (meter) 782
Semi-minor axis of confidence ellipse (meter) 710
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi) 186
Circular confidence region, given by single value of horizontal uncertainty (meter) 780
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 61
Number of associated phases, regardless of their use for origin computation 36
Number of defining phases 36
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.38
Epicentral distance of station closest to the epicenter (degree) 0.17087
Epicentral distance of station farthest from the epicenter (degree) 0.86515
Number of stations at which the event was observed 24
Number of stations from which data was used for origin computation 24
Magnitudes information

ML:2

Field Value
Value 2
Uncertainty 0.2
Num. used stations 35
Type of magnitude ML
Reference to an origin 55008271
Agency INGV
Autore Sala Sismica INGV-Roma
Time of creation (UTC) 2018-03-31 22:48:33

ML:2.1

Field Value
Value 2.1
Uncertainty 0.3
Num. used stations 40
Type of magnitude ML
Reference to an origin 66163161
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2019-03-04 16:52:37
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance Takeoff_angle Residual Weight
IV.MURB.HHZ. 2018-03-31T22:40:08.79 0.6 undecidable manual S 71 0.7311 50 0.51 41
IV.ATMI.HHZ. 2018-03-31T22:40:04.07 1.0 undecidable manual S 58 0.5918 50 -0.08 23
IV.CSNT.HHZ. 2018-03-31T22:40:00.38 0.6 undecidable manual S 335 0.4964 50 -0.94 36
IV.PIEI.HHZ. 2018-03-31T22:40:00.85 0.6 undecidable manual P 53 0.8651 50 0.59 39
IV.APEC.HHZ. 2018-03-31T22:39:59.62 0.6 undecidable manual P 49 0.8139 50 0.23 43
IV.PARC.HHZ. 2018-03-31T22:39:59.05 0.3 undecidable manual P 37 0.7887 50 0.09 67
IV.ATPI.EHZ. 2018-03-31T22:39:58.24 0.1 undecidable manual P 54 0.7374 50 0.17 88
IV.RIBO.EHZ. 2018-03-31T22:39:58.00 0.6 undecidable manual S 259 0.3948 50 -0.32 46
IV.MGAB.HHZ. 2018-03-31T22:39:58.29 0.3 undecidable manual S 106 0.4065 50 -0.36 68
IV.BADI.EHZ. 2018-03-31T22:39:57.17 0.6 undecidable manual P 45 0.6871 50 -0.05 46
IV.SSP9.EHZ. 2018-03-31T22:39:57.70 0.6 undecidable manual P 36 0.6826 50 0.56 41
IV.MURB.HHZ. 2018-03-31T22:39:57.95 1.0 undecidable manual P 71 0.7311 50 -0.02 23
IV.CAFI.HHZ. 2018-03-31T22:39:57.66 0.6 undecidable manual S 43 0.4173 50 -1.32 30
IV.ATVO.HHZ. 2018-03-31T22:39:57.60 0.1 undecidable manual P 59 0.7024 50 0.12 90
IV.ATMI.HHZ. 2018-03-31T22:39:56.88 0.6 undecidable manual P 58 0.5918 50 1.3 30
IV.CASP.HHZ. 2018-03-31T22:39:55.98 0.6 undecidable manual P 246 0.5711 50 0.75 39
IV.OSSC.HHZ. 2018-03-31T22:39:54.47 0.1 undecidable manual P 334 0.5558 50 -0.5 85
IV.TRIF.HHZ. 2018-03-31T22:39:54.86 0.6 undecidable manual P 281 0.5009 50 0.82 38
IV.MCIV.HHZ. 2018-03-31T22:39:53.37 0.6 undecidable manual S 163 0.2545 50 -0.79 40
IV.CSNT.HHZ. 2018-03-31T22:39:53.34 0.1 undecidable manual P 335 0.4964 50 -0.61 83
IV.CAFI.HHZ. 2018-03-31T22:39:52.17 0.1 undecidable manual P 43 0.4173 50 -0.43 89
IV.MGAB.HHZ. 2018-03-31T22:39:52.21 0.3 undecidable manual P 106 0.4065 50 -0.2 70
IV.RIBO.EHZ. 2018-03-31T22:39:52.54 0.1 undecidable manual P 259 0.3948 50 0.31 92
TV.SF01.EHZ. 2018-03-31T22:39:52.26 0.6 undecidable manual S 183 0.2113 113 -0.45 46
TV.SF03.EHZ. 2018-03-31T22:39:52.79 0.3 undecidable manual S 160 0.2338 111 -0.73 62
IV.ARCI.HHZ. 2018-03-31T22:39:51.81 0.6 undecidable manual S 204 0.1862 115 -0.03 51
TV.SF04.EHZ. 2018-03-31T22:39:51.81 0.6 undecidable manual S 162 0.197 114 -0.39 47
IV.FROS.HHZ. 2018-03-31T22:39:51.60 0.1 undecidable manual P 301 0.3597 50 -0.02 98
IV.SACS.HHZ. 2018-03-31T22:39:51.60 0.1 undecidable manual P 125 0.2986 50 1.03 72
TV.SF11.HHZ. 2018-03-31T22:39:50.95 0.3 undecidable manual S 154 0.1709 117 -0.36 71
TV.SF01.EHZ. 2018-03-31T22:39:49.17 0.1 positive manual P 183 0.2113 113 0.19 98
TV.SF03.EHZ. 2018-03-31T22:39:49.51 0.1 undecidable manual P 160 0.2338 111 0.06 100
IV.MCIV.HHZ. 2018-03-31T22:39:49.95 0.1 undecidable manual P 163 0.2545 50 0.13 98
TV.SF11.HHZ. 2018-03-31T22:39:48.49 0.3 undecidable manual P 154 0.1709 117 0.31 72
IV.ARCI.HHZ. 2018-03-31T22:39:48.67 0.1 undecidable manual P 204 0.1862 115 0.19 98
TV.SF04.EHZ. 2018-03-31T22:39:48.87 0.1 undecidable manual P 162 0.197 114 0.18 98
Station Magnitude and Amplitude
SCNL mag Generic_amplitude Period Type Category Unit Time_window_reference
TV.SF04.EHE. ML:2.9 0.005735 1.82 AML other m 2018-03-31T22:39:53.96
TV.SF01.EHE. ML:2.4 0.001725 0.3 AML other m 2018-03-31T22:39:53.66
TV.SF01.EHN. ML:2.6 0.002265 0.26 AML other m 2018-03-31T22:39:53.50
IV.ARCI.HHN. ML:2 0.000752 0.3 AML other m 2018-03-31T22:39:53.66
IV.ARCI.HHE. ML:1.9 0.000628 0.72 AML other m 2018-03-31T22:39:54.92
IV.MCIV.HHN. ML:2.3 0.0010045 0.92 AML other m 2018-03-31T22:39:54.39
IV.MCIV.HHE. ML:2.2 0.00086 1.76 AML other m 2018-03-31T22:39:54.89
IV.CAFI.HHN. ML:1.8 0.000196 0.28 AML other m 2018-03-31T22:39:58.75
IV.CAFI.HHE. ML:2 0.000284 0.4 AML other m 2018-03-31T22:39:58.77
IV.CAFI.HNE. ML:2 0.0002807981 0.8832 AML other m 2018-03-31T22:39:58.77
IV.SACS.HHN. ML:1.7 0.0002175 0.62 AML other m 2018-03-31T22:39:59.15
IV.SACS.HNN. ML:1.7 0.0002085 0.64 AML other m 2018-03-31T22:39:59.15
IV.FROS.HHN. ML:2 0.0003635 1.34 AML other m 2018-03-31T22:39:59.68
IV.SACS.HNE. ML:1.8 0.000245 0.28 AML other m 2018-03-31T22:39:59.66
IV.SACS.HHE. ML:1.8 0.000241 0.28 AML other m 2018-03-31T22:39:59.66
IV.CAFI.HNN. ML:1.8 0.00019254235 0.1888 AML other m 2018-03-31T22:39:59.75
IV.MGAB.HNN. ML:2 0.0003005 0.16 AML other m 2018-03-31T22:40:00.30
IV.MGAB.HHN. ML:2 0.000292 1.34 AML other m 2018-03-31T22:40:00.30
IV.CSNT.HHN. ML:1.9 0.000196 0.82 AML other m 2018-03-31T22:40:01.49
IV.CSNT.HHE. ML:2 0.000228 0.2 AML other m 2018-03-31T22:40:01.15
IV.FROS.HHE. ML:2 0.000387 0.7 AML other m 2018-03-31T22:40:01.11
IV.MGAB.HHE. ML:2 0.0002895 0.76 AML other m 2018-03-31T22:40:02.61
IV.MGAB.HNE. ML:1.9 0.0002545 0.32 AML other m 2018-03-31T22:40:02.61
IV.ATMI.HHE. ML:2.4 0.000503 0.24 AML other m 2018-03-31T22:40:04.53
IV.ATMI.HHN. ML:2.7 0.000926 0.3 AML other m 2018-03-31T22:40:05.71
IV.MURB.HNN. ML:3.2 0.00215 0.3 AML other m 2018-03-31T22:40:10.16
IV.MURB.HHN. ML:3.2 0.002175 0.3 AML other m 2018-03-31T22:40:10.16
IV.MURB.HHE. ML:3 0.001225 0.3 AML other m 2018-03-31T22:40:10.65
IV.MURB.HNE. ML:0 0.0010065 1.04 AML other m 2018-03-31T22:40:10.66
IV.BADI.EHN. ML:2 0.0001625 0.62 AML other m 2018-03-31T22:40:11.10
IV.ATPI.EHE. ML:2 0.000118 0.82 AML other m 2018-03-31T22:40:12.65
IV.ATVO.HHE. ML:2 0.0001525 1.08 AML other m 2018-03-31T22:40:12.94
IV.ATVO.HHN. ML:2 0.00013025 0.44 AML other m 2018-03-31T22:40:12.25
IV.ATPI.EHN. ML:2 0.0001405 0.5 AML other m 2018-03-31T22:40:13.10
IV.PARC.HHE. ML:2 0.000112 1.38 AML other m 2018-03-31T22:40:13.28
IV.APEC.HHE. ML:2.1 0.000154 0.62 AML other m 2018-03-31T22:40:15.96
IV.APEC.HHN. ML:2.1 0.00015 0.66 AML other m 2018-03-31T22:40:16.50
IV.PARC.HHN. ML:2 0.0001358 0.46 AML other m 2018-03-31T22:40:16.87
IV.PIEI.HHN. ML:1.9 8.32E-5 0.52 AML other m 2018-03-31T22:40:17.40
IV.PIEI.HHE. ML:1.8 6.14E-5 1.3 AML other m 2018-03-31T22:40:18.13
TDMT - Time Domain Moment Tensor
Focal Mechanism in the area
Focal Mechanisms

Focal Mechanisms *

This map reports the focal mechanisms since 1977 in the region. The white and red beach ball symbols are mechanisms determined using the Regional Centroid Moment Tensor (RCMT, http://www.bo.ingv.it/RCMT) and are determined for earthquakes with magnitude larger than 4.5 in the Euro-Mediterranenan area. Occasionally, when there is a good source-receiver geometry of the target earthquake, the RCMT can be obtained also for earthquakes with magnitude larger than 4.0. The blue and white beach ball symbols indicate the mechanisms obtained from application of the Time Domain Moment Tensor (TDMT, http://cnt.rm.ingv.it/tdmt.html). This technique is used for M ≥ 3.5. The size of the beach ball sysmbol scales with the calculated moment magnitude, Mw.
Download
Type Description Link
QuakeML - small Event, Origin, FocalMechanism Download
QuakeML - full Event, Origin, FocalMechanism, Amplitude, Arrival, Pick, Station Magnitude Download
Waveforms Seismic signals in full SEED format Download