| 07 Nov 2025
A thorough review of the May 5, 1990 earthquake (southern Italy): constraints from macroseismology and insights from hydrology
Abstract. The May 5, 1990, Potenza earthquake (Mw 5.77) was a significant event for southern Italy, despite its moderate magnitude and limited damage. Previous macroseismic studies of this earthquake contained inconsistent and often exaggerated intensity values, particularly in areas far from the epicentre. Our analysis reveals that some overestimated intensities were caused by the overlapping damage patterns from previous earthquakes, due to the tendency to emphasize pre-existing or unrepaired damage, or attribute them to the most recent earthquake. In this respect, we re-evaluate all available data from original sources and compile a new and robust dataset comprising 1393 intensity values, assessed using both MCS and EMS-98 scales. This updated dataset shows a general decrease in higher intensity values compared to previous assessments, especially within 150 km of the epicentre. We also identify new data sources and remove unreliable entries. Recalculated macroseismic epicentres are in agreement with the instrumental estimate (i.e., 7.3 km using MCS data), while macroseismic magnitudes (Mw 5.05–5.19) are lower than the instrumental one. Additionally, we collect extensive observations of seismically-induced hydrological changes. These hydrological effects provide independent magnitude estimates ranging from M 4.9 to 5.7 for liquefaction and M 5.2 for streamflow responses. This comprehensive re-evaluation significantly enhances the accuracy and usefulness of the macroseismic and environmental data for future seismological research.
Title: A thorough review of the May 5, 1990 earthquake (southern Italy): constraints from macroseismology and insights from hydrology
Author(s): Andrea Antonucci et al.
MS No.: egusphere-2025-5343
MS type: Research article
General comments
The paper brings a new insight into consequences of 5 May 1990 Potenza earthquake. The new analysis of the existing datasets, with the addition of new primary sources, shows an updated picture of this damaging event. Bringing hydrological effects into the picture allows us to have an additional insight into the earthquake effects in the wider epicentral area.
Please spell-check the text carefully, using UK English for all used terms.
The date format: the use of the scientific date format is recommended (DD Month YEAR) in the entire paper.
Specific comments
Site vs. locality: I have been researching the use of both terms, and it seems that there is no consensus which one is more proper for naming an inhabited place. Several sciences (e.g. archaeology, palaeontology etc) use these terms not as synonyms, but as a definition of the size of the examined area. In my head locality relates to man-built habitations, and a site can be just anything, from a camp site to intended site for a new shopping mall; but it’s not necessarily true. However, I suggest that the authors read the text again and unify the use of the chosen term.
The title of the paper: as the earthquake in focus is being referenced as Potenza earthquake throughout the text, this name should be used in the title, too. Consider changing it into " A thorough review of the 5 May 1990 Potenza (Southern Italy) earthquake: constraints from macroseismology and insights from hydrology”
Epicentral intensity I0 should be written with zero as subscript (see https://gfzpublic.gfz.de/rest/items/item_4011_4/component/file_4012/content)
When seismologists talk about all sorts of things that can be felt and/or leave a trace on the seismograms, they are named as events. However, when we talk of a known earthquake, to avoid any possible confusion, it’s called an earthquake and not an event.
Line 8 and further in the text: just out of curiosity, is the precision with which intensities are evaluated enough to allow us expressing the Mw with two decimal places?
Line 13: “intensity values”. It should be clarified, here as well in the rest of the text, that the authors are talking about macroseismic data points (MDPs). Please check and correct all the places it applies to (line 50 and forward). It is a good place to explain what MDPs are, as the abbreviation is used already in Fig. 1 and explained only later in the text.
Line 56: consider replacing “provoked a very large perception” with “was widely felt”
Figure 1: MDP – already mentioned. Data points with Imax are not visible in the maps. Consider adding the number of Imax data points and the Imax intensity in the caption.
Line 84: Sentence starting with “This methodology involved sending…” should be translated from Italian in a more precise way.
Line 112: abbreviation GOM24 is not explained
Figure 4: absolutely not readable, at least in the pdf I am working with.
Consider changing “damage and effects on the environment” to “buildings and nature”.
Line 146: Guidoboni et al. (2007) not in the References
Line 164: Consider replacing “we assessed a total of 1393 new intensity values, which were compiled from a careful” with “a total of 1393 MDPs were assessed, as a result of a careful”.
Figure 6. Caption should read “distributions for 5 May 1990 Potenza earthquake in the…” or something similar.
Line 179: The last sentence needs a bit more details, at least 1-2 sentences describing very shortly what those 2 papers are about.
Line 195: “In two localities” – name them.
Line 202: consider replacing “the new assessment is” with “the intensities assessed in this study are”
Table 1. Consider adding another column with Imax.
Line 225: instead of “see Section 2” there should be “see Figure 4”, I presume?
Figure 10: the background of the map is too dark and does not allow the tiny font to be readable
Line 237: Hydrological Annals – not in the References
Line 241: consider replacing “To further constrain” with “In order to constrain further”
Line 254: replace “effects respectively” with “effects, respectively”.
Line 255: the section gives good overview of the paper, but there’s not much discussion.
Table S1: could you, instead of the category NC, differentiate the effects more and use the descriptive terms F (felt), damage (D) etc, as suggested in https://emidius.eu/MIDOP/manual/input_data_preparation/input_data_table_formats.php ?
Line 267: rephrase the sentence starting with “We compute”. Are you talking about the intensity assessment of the MDPs or the calculation of the focal parameters?
Line 283: “in March 2025” – date? Where?
Appendix A
WGS84 not explained
Lat – add °N
Lon – add °E
A: add ING
Technical corrections
Figure 4: absolutely not readable, at least in the pdf I am working with.
Figure 10: the background of the map is too dark and does not allow the tiny font to be readable
Line 239: replace “kilometers-slightly” with “kilometres – slightly”