Earthquake with magnitude of Md 2.2 on date 20-08-1988 and time 07:33:20 (Italy) in region 4 km W Massa Martana (PG)

A magnitude Md 2.2 earthquake occured in region: 4 km W Massa Martana (PG), on

  • 20-08-1988 05:33:20 (UTC)
  • 20-08-1988 07:33:20 (UTC +02:00) Italian time

and geographic coordinates (lat, lon) 42.7870, 12.4800 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
Massa Martana PG 4 3770 3770
Todi PG 6 16851 20621
Giano dell'Umbria PG 10 3846 24467
Acquasparta TR 12 4778 29245
Monte Castello di Vibio PG 12 1567 30812
Fratta Todina PG 12 1839 32651
Collazzone PG 13 3473 36124
Avigliano Umbro TR 15 2558 38682
Gualdo Cattaneo PG 15 6155 44837
Montecastrilli TR 15 5022 49859
Castel Ritaldi PG 16 3278 53137
Marsciano PG 18 18902 72039
Montefalco PG 19 5679 77718
San Venanzo TR 20 2218 79936
Bevagna PG 20 5081 85017
San Gemini TR 20 5018 90035

Municipalities with at least 50000 inhabitants

An earthquake occurred to
26 Km SW of Foligno (57155 inhabitants)
29 Km NW of Terni (111501 inhabitants)
36 Km S of Perugia (166134 inhabitants)
51 Km NE of Viterbo (67173 inhabitants)
90 Km NW of L'Aquila (69753 inhabitants)
90 Km N of Guidonia Montecelio (88673 inhabitants)
90 Km SE of Arezzo (99543 inhabitants)
95 Km N of Tivoli (56533 inhabitants)
96 Km NE of Civitavecchia (52991 inhabitants)
99 Km N of Roma (2864731 inhabitants)
Recent and historical seismicity
Seismic hazard
Shakemap
Felt maps
Locations history
Type Magnitude Date and Time (UTC) Latitude Longitude Depth (km) Published time (UTC) Author Location ID
Bulletin
Rev1000
Md 2.2
ML-VAX 1.7
1988-08-20
05:33:20
42.787 12.48 10 2013-07-15
08:41:04
Bollettino Sismico Italiano INGV 75869
Preferred location and magnitude until now.
Origin information

Origin

Field Value
Time (UTC) 1988-08-20 05:33:20 ± 0.087
Latitude 42.7870 ± 0.0022
Longitude 12.4800 ± 0.0095
Depth (km) 10 (operator assigned)
Evaluation mode of Origin manual
Evaluation status of Origin reviewed
Version 1000 -> BULLETIN-VAX
Event type earthquake
Origin ID 75869

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) 818.1
Confidence level of the uncertainty (%) 68

Quality

Field Value
Largest azimuthal gap in station distribution as seen from epicenter (degree) 224
Number of associated phases, regardless of their use for origin computation 6
Number of defining phases 6
RMS of the travel time residuals of the arrivals used for the origin computation (sec) 0
Epicentral distance of station closest to the epicenter (degree) 0.00267
Epicentral distance of station farthest from the epicenter (degree) 0.00567
Number of stations at which the event was observed 3
Number of stations from which data was used for origin computation 3
Magnitudes information

Md:2.2

Field Value
Value 2.2
Uncertainty
Num. used stations 1
Type of magnitude Md
Reference to an origin 75869
Agency INGV
Autore Bollettino Sismico Italiano INGV
Time of creation (UTC) 2013-01-04 18:11:31

ML:1.7

Field Value
Value 1.7
Uncertainty
Num. used stations 1
Type of magnitude ML
Reference to an origin 75869
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
--.CM8.Z. 1988-08-20T05:33:42.99 10.0 undecidable manual SG 49 0.6327 0.02 0.9
--.MNS.Z. 1988-08-20T05:33:36.38 10.0 undecidable manual SG 159 0.4218 -0.02 0.7
--.CM8.Z. 1988-08-20T05:33:33.62 10.0 undecidable manual PG 49 0.6327 0.05 1.3
--.ASS.Z. 1988-08-20T05:33:32.15 10.0 undecidable manual SG 24 0.2997 -0.2 0.1
--.MNS.Z. 1988-08-20T05:33:29.75 10.0 undecidable manual PG 159 0.4218 -0.03 1.7
--.ASS.Z. 1988-08-20T05:33:27.50 10.0 undecidable manual PG 24 0.2997 0.06 1.4
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