1997 Umbria Earthquake

I just threw this page from the Umbria Observatory into Google Translate (not bad) and quickly cleaned it up

http://www.osservatorioricostruzione.regione.umbria.it/canale.asp?id=223

Started in September 1997 an earthquake struck the end of the Apennine Mountains that straddles the Marche and Umbria, where destructive earthquakes had oalready ccurred in the past. The intensity of the strongest shock (5.8 Richter – Mercalli IX), is in line with those of historical earthquakes in the past that have affected the eastern Umbria.

Already as early as May of 1997, there had been earthquakes in the areas of Martani and the area of Cerreto di Spoleto. The shock of greatest intensity recorded was a seventh degree Mercalli (4.5 Richter) with epicenter near Massa Martana.

The first earthquakes that affected the northern part of the Apennines, Umbria – Marche, occurred between 23-27 August 1997, with a series of events of small magnitude (Richter 2.5 to 3).
On September 4, an event of magnitude 4.4 on the Richter scale affected the same epicentral area of the September 26 quake, with a number of repeats in the following days.

On September 26 the two main events in the sequence occurred: the first of Colfiorito and Cesi at 2.33, with intensity VIII – IX Mercalli (5,6 R), the second between Annifo and Colfiorito (5,8 R), the 11.40 am, with Mercalli intensity IX.

The earthquakes continued into the early days of October with events of intensity up to 4.9 Mercalli (October 3 in the area of Nocera Umbra 4.8 M, 4 October in an area Sellano – Preci, marking the beginning of the shift to the of the southern portion of the area; October 7 and October 12 M 4.9 4.5 forever in the Sellano – Preci).

On 14 October at 17:23, there was a VII – VIII degree Mercalli (5.5 Richter) erthquake in the area of Sellano – Preci, which is considered the third of the sequence.

A new and significant earthquake was recorded March 26, 1998, at 17:26, with epicenter in Gualdo Tadino, of Mercalli intensity VII (5.4 Richter) and characterized by a high depth (45 km).
This shock was followed, by two others on April 3 and 5, both with intensity of VI-VII degree Mercalli (R 4.7 – 4.5 R), again located in the area of Gualdo Tadino but with a depth of approximately km 10 and, therefore, much more felt in the surface.

Summary of seismic sequence Date
Time
Mercalli Intensity (MCS)
Magnitude
Nearest epicenter
 
 May 5, 1997
  14.03
  V
  3.7
  Mass martana
 
May 12, 1997
 15.50
  VII
 4.5
 Mass martana
 
September 4, 1997
  00.07
 VI – VII
 4.4
 Colfiorito
 
September 26, 1997
 02.33
  VIII – IX
  5.6
 Cesi
 
September 26, 1997
 11.40
 IX
 5.8
  Annifo
 
October 2, 1997
  21.38
 V – VI
 3.9
 Sansepolcro
 
October 3, 1997
  10.55
 VII
 5.0
 Colfiorito
 
October 4, 1997
 18.13
 VI
 4.5
 Sellano – Preci
 
October 7, 1997
 01.24
 VII – VIII
 5.3
 Colfiorito
 
October 12, 1997
 13.08
 VI – VII
 5.1
 Sellano – Preci
 
October 14, 1997
 17.23
 VII – VIII
 5.5
 Sellano – Preci
 
November 9, 1997
 20.07
 VI – VII
 4.4
 Sellano – Preci
 
March 26, 1998
 17.26
  VII
 5.4
 Gualdo Tadino
 
April 3, 1998
 09.26
 VI – VII
  4,7″ c=”> 4.7  ” b=”> 4,7″>> 4.7
 Gualdo Tadino
 
April 5, 1998
 17.52
 VI – VII
 4.5
 Gualdo Tadino
 
June 5, 1998
 23.57
 V – VI
 4.1
  Gualdo Tadino
 
June 26, 1998
 02.32
  V – VI
  4.0
 Colfiorito