Istituto Nazionale di Geofisica e Vulcanologia

Earthquake with magnitude of Md 3.3 on date 03-04-1991 and time 15:13:34 (UTC) in region 8 km NE L'Aquila (AQ)

A magnitude Md 3.3 earthquake occured in region: 8 km NE L'Aquila (AQ), on

  • 03-04-1991 15:13:34 (UTC)
  • 03-04-1991 17:13:34 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.3990, 13.4720 at 5 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
L'Aquila AQ 8 69753 69753
Poggio Picenze AQ 10 1136 70889
Fossa AQ 12 721 71610
Barisciano AQ 13 1828 73438
Ocre AQ 13 1167 74605
Sant'Eusanio Forconese AQ 13 394 74999
San Demetrio ne' Vestini AQ 14 1854 76853
Pizzoli AQ 15 4326 81179
Villa Sant'Angelo AQ 15 424 81603
Pietracamela TE 16 271 81874
Santo Stefano di Sessanio AQ 16 111 81985
Lucoli AQ 16 1011 82996
Crognaleto TE 17 1297 84293
Barete AQ 17 737 85030
Prata d'Ansidonia AQ 17 496 85526
Scoppito AQ 18 3727 89253
Fano Adriano TE 18 296 89549
Rocca di Cambio AQ 18 533 90082
Fagnano Alto AQ 18 418 90500
Tornimparte AQ 18 3187 93687
Capitignano AQ 20 665 94352
Isola del Gran Sasso d'Italia TE 20 4773 99125
San Pio delle Camere AQ 20 661 99786
Campotosto AQ 20 542 100328

Municipalities with at least 50000 inhabitants

An earthquake occurred to
8 Km NE of L'Aquila (69753 inhabitants)
35 Km SW of Teramo (54892 inhabitants)
57 Km W of Montesilvano (53738 inhabitants)
57 Km W of Chieti (51815 inhabitants)
61 Km W of Pescara (121014 inhabitants)
70 Km E of Terni (111501 inhabitants)
74 Km NE of Tivoli (56533 inhabitants)
76 Km NE of Guidonia Montecelio (88673 inhabitants)
88 Km SE of Foligno (57155 inhabitants)
98 Km NE of Velletri (53303 inhabitants)
99 Km NE of Roma (2864731 inhabitants)
Recent and historical seismicity

These maps show the seismic activity in different time intervals, before the seismic event to which they refer. Data reported in the first two maps come from the analysis carried out in real time by the personnel of the INGV Operating Rooms, immediately after each earthquake. The third map shows data from 1985 to the date of the earthquake: the locations are reviewed by the seismological analysts of the INGV Italian Seismic Bulletin (Bollettino Sismico Italiano dell’INGV). The localization parameters (hypocentral coordinates and magnitude) are the best possible estimate with the data available to the INGV, but are constantly updated according to further data that become available. The location and magnitude parameters, subsequently reviewed by seismological analysts, may vary.

Earthquakes of the 3 days preceding this event

Earthquakes of the 3 days preceding this event

This map shows the earthquake epicenters with magnitude ≥ 0.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, in the 72 hours preceding this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes of the 90 days preceding this event

Earthquakes of the 90 days preceding this event

This map shows the earthquake epicenters with magnitude ≥ 2.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, in the 90 days preceding this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes from 1985 to the date of the event

Earthquakes from 1985 to the date of the event

This map shows the earthquake epicenters with magnitude ≥ 3.0, localized with data recorded by the National Seismic Network and other collaborative networks both in Italy and in neighboring countries, from 1985 to the date of this event. The size of the circle indicates the different classes of magnitude. The colors indicate the different time intervals preceding the seismic event. The black and white star is the epicenter of the current earthquake.
Earthquakes since 1000 AD until 2019

Earthquakes since 1000 AD until 2019

This map shows the epicenters of the historical earthquakes catalogue CPT15 (Catalogo Parametrico dei Terremoti Italiani, 2015 version 3.0, https://doi.org/10.13127/cpti/cpti15.3) since 1000 AD until 2019. The size of the square indicates the different classes of magnitude. For earthquakes with magnitude ≥ 6.0, it is also shown the year of occurrence and the magnitude value. The black and white star is the epicenter of the current earthquake.
Seismic hazard

Seismic hazard maps provide probabilistic estimates of the earthquake ground shaking exceeding a given threshold in a given geographic region within a given time window. Thus, it is not a deterministic prediction - a target that may be never reached given the complexity of the earthquake physical phenomenon - nor of the maximum expected earthquake since this has extremely low probabilities to occur.

In 2004, it was published the seismic hazard map of Italy (http://zonesismiche.mi.ingv.it) that provides a picture of the most hazardous geographic regions. The seismic hazard map of Italy (GdL MPS, 2004; rif. Ordinanza PCM del 28 aprile 2006, n. 3519, All. 1b) provides the 10% probability of exceedance in 50 years of the horizontal acceleration at rock sites (i.e., Vs30>800 m/s; cat. A, 3.2.1 of the D.M. 14.09.2005).

The colours indicate the various values of the ground acceleration that have 10% to be exceeded within 50 years. In general, the colours associated to low values of acceleration refer to areas that are less hazardous and stronger earthquakes repeat less frequently although they may still occur.

Seismic hazard map

Seismic hazard map

This map shows the seismic hazard map of Italy for the region where the earthquake occurred.
Shakemap
Felt maps
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
Bulletin
Rev1000 		Md 3.3
ML-VAX 2.8 		1991-04-03
15:13:34		 42.399 13.472 5 2013-07-15
08:41:04		 Bollettino Sismico Italiano INGV 138589
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1991-04-03 15:13:34 ± 0.191
Latitude 42.3990 ± 0.0109
Longitude 13.4720 ± 0.0234
Depth (km) 5 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 138589

Uncertainty

Field Value
Preferred uncertainty description horizontal uncertainty
Semi-major axis of confidence ellipse (meter)
Semi-minor axis of confidence ellipse (meter)
Azimuth of major axis of confidence ellipse. Measured clockwise from South-North direction at epicenter (gradi)
Circular confidence region, given by single value of horizontal uncertainty (meter) 2274.7
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 97
Number of associated phases, regardless of their use for origin computation 41
Number of defining phases 41
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0.9
Epicentral distance of station closest to the epicenter (degree) 0.00057
Epicentral distance of station farthest from the epicenter (degree) 0.06055
Number of stations at which the event was observed 31
Number of stations from which data was used for origin computation 31
Magnitudes information

Md:3.3

Field Value
Value 3.3
Uncertainty
Num. used stations 8
Type of magnitude Md
Reference to an origin 138589
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 19:09:19

ML:2.8

Field Value
Value 2.8
Uncertainty
Num. used stations 9
Type of magnitude ML
Reference to an origin 138589
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2015-04-28 13:07:13
Picking and Arrival
SCNL Time Uncertainty Polarity Evaluation_mode Phase Azimuth Distance(km) Takeoff_angle Residual Weight
--.KHC.Z. 1991-04-03T15:15:14.59 10.0 undecidable manual PN 0 6.7155 0.97 0.5
--.FVI.Z. 1991-04-03T15:14:39.50 10.0 undecidable manual PN 353 4.218 0.3 1
--.CTI.Z. 1991-04-03T15:14:34.99 10.0 undecidable manual PN 340 3.8628 0.56 1
--.BOB.Z. 1991-04-03T15:14:34.00 10.0 undecidable manual PN 310 3.7518 1.22 0.6
--.TRI.Z. 1991-04-03T15:14:27.00 10.0 undecidable manual PN 3 3.3078 0.24 1.2
--.BRT.Z. 1991-04-03T15:14:26.11 10.0 undecidable manual PN 117 3.1413 1.73 0.4
--.RIY.Z. 1991-04-03T15:14:22.50 10.0 undecidable manual PN 12 3.0081 -0.14 1.3
--.BDI.Z. 1991-04-03T15:14:18.60 10.0 undecidable manual PN 309 2.664 0.11 1.4
--.MME.Z. 1991-04-03T15:14:18.70 10.0 undecidable manual PN 312 2.6973 0.4 1.3
--.CDT.Z. 1991-04-03T15:14:16.50 10.0 undecidable manual PN? 121 2.4642 1.33 0.3
--.SGO.Z. 1991-04-03T15:14:14.53 10.0 undecidable manual PN 142 2.2866 1.75 0.4
--.AOI.Z. 1991-04-03T15:14:14.30 10.0 undecidable manual SN 4 1.1544 0.62 0.6
--.ARV.Z. 1991-04-03T15:14:13.44 10.0 undecidable manual SN 340 1.1544 -0.52 0.7
--.FIR.Z. 1991-04-03T15:14:11.00 10.0 undecidable manual PN 311 2.109 0.6 1.4
--.MS1.Z. 1991-04-03T15:14:10.00 10.0 undecidable manual PN 109 1.9536 1.83 0.4
--.DUI.Z. 1991-04-03T15:14:09.46 10.0 undecidable manual SG 134 1.0323 -1.25 0.4
--.SFI.Z. 1991-04-03T15:14:07.80 10.0 undecidable manual PN 322 1.9092 0.26 1.7
--.PGD.Z. 1991-04-03T15:14:07.80 10.0 undecidable manual PN 319 1.9425 -0.24 1.7
--.RSM.Z. 1991-04-03T15:14:06.10 10.0 undecidable manual PN 334 1.6983 1.41 0.8
--.RMP.Z. 1991-04-03T15:14:04.57 10.0 undecidable manual SG 224 0.8214 0.98 0.5
--.SSO.Z. 1991-04-03T15:14:04.60 10.0 undecidable manual SG 357 0.888 -1.4 0.3
--.CRE.Z. 1991-04-03T15:14:03.83 10.0 undecidable manual PN 318 1.6428 -0.09 1.8
--.RDP.Z. 1991-04-03T15:14:03.59 10.0 undecidable manual SG 221 0.8436 -1.02 0.5
--.FG2.Z. 1991-04-03T15:14:01.89 10.0 undecidable manual PN 114 1.3875 1.59 0.6
--.CP9.Z. 1991-04-03T15:13:59.16 10.0 undecidable manual SG 215 0.6549 0.64 0.6
--.SDI.Z. 1991-04-03T15:13:59.73 10.0 undecidable manual SG 159 0.7326 -1.13 0.4
--.RFI.Z. 1991-04-03T15:13:57.95 10.0 undecidable manual PN 160 1.1544 0.72 1.5
--.MNS.Z. 1991-04-03T15:13:56.50 10.0 undecidable manual SG 268 0.5772 0.46 0.7
--.ARV.Z. 1991-04-03T15:13:55.65 10.0 undecidable manual PN 340 1.1544 -1.61 0.6
--.AOI.Z. 1991-04-03T15:13:55.70 10.0 undecidable manual PN 4 1.1544 -1.39 0.8
--.DUI.Z. 1991-04-03T15:13:54.31 10.0 undecidable manual PG 134 1.0323 -1.07 1.1
--.RDP.Z. 1991-04-03T15:13:51.47 10.0 undecidable manual PG 221 0.8436 -0.38 1.7
--.AZI.Z. 1991-04-03T15:13:50.20 10.0 undecidable manual SG 183 0.3996 -0.24 0.7
--.RMP.Z. 1991-04-03T15:13:50.23 10.0 undecidable manual PG 224 0.8214 -1.04 1.2
--.SSO.Z. 1991-04-03T15:13:50.80 10.0 undecidable manual PG 357 0.888 -1.86 0.4
--.SDI.Z. 1991-04-03T15:13:48.51 10.0 negative manual PG 159 0.7326 -1.18 2
--.MNS.Z. 1991-04-03T15:13:47.50 10.0 undecidable manual PG 268 0.5772 0.59 1.6
--.CP9.Z. 1991-04-03T15:13:47.11 10.0 undecidable manual PG 215 0.6549 -1.22 1
--.AZI.Z. 1991-04-03T15:13:42.84 10.0 positive manual PG 183 0.3996 -0.83 2.7
--.ALP.Z. 1991-04-03T15:13:41.00 10.0 undecidable manual PG 10 0.3885 -2.09 0.3
--.AQU.Z. 1991-04-03T15:13:37.00 10.0 negative manual PG 228 0.0666 0.75 2.9
TDMT - Time Domain Moment Tensor
Fault Plane solutions in the area
Fault Plane solutions

Fault Plane solutions

The map reports the fault plane solutions for earthquakes in the region from 1977 to the date of this event. Red moment tensors are determined using the Regional Centroid Moment Tensor technique (RCMT, http://www.bo.ingv.it/RCMT) applied for earthquakes with magnitude larger than 4.5 in the Euro-Mediterranenan area. Occasionally, when a station azimuthal coverage exists RCMTs can be obtained also for earthquakes with magnitude down to 4.0. The gray moment tensors are obtained with the Time Domain Moment Tensor method (TDMT, /tdmt). This technique is applied to earthquakes with magnitude ML greater than 3.2, when it is possible. The size of symbols 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