Estimating the Magnitude of Historical Earthquakes from Macroseismic Intensity Data: New Relationships for the Volcanic Region of Mount Etna (Italy)

2011 ◽  
Vol 82 (4) ◽  
pp. 533-544 ◽  
Author(s):  
R. Azzaro ◽  
S. D'Amico ◽  
T. Tuve
Keyword(s):  
Historical Earthquakes ◽  
Macroseismic Intensity ◽  
Mount Etna ◽  
Intensity Data ◽  
Volcanic Region

scholarly journals Inferring the depth of pre-instrumental earthquakes from macroseismic intensity data: a case-history from Northern Italy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Paola Sbarra ◽  
Pierfrancesco Burrato ◽  
Patrizia Tosi ◽  
Paola Vannoli ◽  
Valerio De Rubeis ◽  
...  
Keyword(s):  
Focal Depth ◽  
Historical Earthquakes ◽  
Northern Italy ◽  
Macroseismic Intensity ◽  
Intensity Data ◽  
Seismogenic Source ◽  
Seismogenic Faults ◽  
Intensity Field ◽  
Different Depths ◽  
Recent Earthquakes

Abstract Determining the hypocentral depth of pre-instrumental earthquakes is a long-standing geophysical issue that still awaits to be elucidated. Using very well documented recent earthquakes we found that the depth of crustal and upper-mantle events correlates well with the slope of the first 50 km of their intensity attenuation curve, regardless of their magnitude. We used this observation to build a magnitude-independent method for calculating the depth of selected historical and early-instrumental earthquakes of northern Italy based on their macroseismic intensity field. Our method relies on both standard intensity data and questionnaire-based data for 20 earthquakes, encompassing a relatively large range of magnitude (Mw 4.0–5.8) and depth (3.0–72.4 km), that occurred in Northern Italy between 1983 and 2019. We then used the method to estimate the depth of 20 older earthquakes that occurred in the same region between 1570 and 1972. Knowing the approximate depth of historical earthquakes is crucial for assigning them to the relevant seismogenic source, especially where seismogenic faults occur at different depths, allowing for a better characterisation of the region’s seismotectonic setting. Knowing the focal depth also allows recalculating the equivalent magnitude, which turns out to be consistently larger for deeper events, suggesting a reassessment of the local seismic hazard.

scholarly journals Macroseismic intensity data of the 22 April 2013 Tenk (Hungary) earthquake

2014 ◽  
Vol 49 (3) ◽  
pp. 283-294
Author(s):  
Gyöngyvér Szanyi ◽  
Zoltán Gráczer ◽  
Erzsébet Győri
Keyword(s):  
Macroseismic Intensity ◽  
Intensity Data

Estimates of magnitudes and short-period wave attenuation of Chinese earthquakes from Modified Mercalli intensity data

1984 ◽  
Vol 74 (3) ◽  
pp. 957-968
Author(s):  
Peishan Chen ◽  
Otto W. Nuttli
Keyword(s):  
Wave Attenuation ◽  
Body Wave ◽  
Empirical Relation ◽  
Historical Earthquakes ◽  
The Body ◽  
Intensity Data ◽  
Mountainous Regions ◽  
Short Period ◽  
Recent Earthquakes ◽  
Period Wave

Abstract Intensity data for Chinese earthquakes are used to estimate the body-wave magnitude, mb, of selected historical earthquakes and to estimate Q0, the 1-sec period Q value of Lg waves for various geographical areas of China. In order to derive the necessary empirical relation between the intensity distribution and mb, data are used from recent earthquakes, for which instrumentally obtained mb values as well as isoseismal maps are available. Average Qo values are approximately 175 for the mountainous regions of southwest China, 550 for southeastern China, and 150 for Taiwan. These values agree qualitatively with those obtained by Evernden (1983) and Chen et al. (1983), who utilized a different method of analysis of the intensity data

scholarly journals INGe: Intensity-ground motion dataset for Italy

2020 ◽  
Author(s):  
Ilaria Oliveti ◽  
Licia Faenza ◽  
Alberto Michelini
Keyword(s):  
Strong Motion ◽  
Data Bank ◽  
Macroseismic Intensity ◽  
Time Span ◽  
Data Repository ◽  
Distance Metrics ◽  
Intensity Data ◽  
Data Set ◽  
Final Data ◽  
Data Source

Abstract. In this paper we present an updated and homogeneous earthquake data set for Italy compiled by joining the Italian Macroseismic Database DBMI15 and the Engineering Strong-Motion (ESM) accelerometric data bank. The database has been compiled through an extensive procedure of selection and revision based on two main steps: 1) the removal of several earthquakes in DBMI15 because the data source has been considered to be largely unreliable and 2) the extraction of all the localities reporting intensity data which are located within 3 km from the accelerograph stations that recorded the data. The final data set includes 323 recordings from 65 earthquakes and 227 stations in the time span 1972–2016. The events are characterized by magnitudes in the range 4.0–6.9 and depths in the range 0.3–45.0 km. Here, we illustrate the data collection and the properties of the database in terms of recording, event and station distributions as well as Mercalli-Cancani-Sieberg (MCS) macroseismic intensity points. Furthermore, we discuss the most relevant features of engineering interest showing several statistics with reference to the most significant metadata (such as moment magnitude, several distance metrics, style of faulting etc). The data set can be downloaded from data repository Zenodo at https://doi.org/10.13127/inge.1 (Oliveti et., 2020).

On the relation between modified Mercalli intensity and body-wave magnitude

1979 ◽  
Vol 69 (3) ◽  
pp. 893-909
Author(s):  
Otto W. Nuttli ◽  
G. A. Bollinger ◽  
Donald W. Griffiths
Keyword(s):  
United States ◽  
South Carolina ◽  
San Francisco ◽  
Body Wave ◽  
Strong Motion ◽  
Historical Earthquakes ◽  
P Wave ◽  
Intensity Data ◽  
Lg Wave ◽  
Body Wave Magnitude

abstract This paper is concerned with estimating body-wave magnitude, mb, from the intensity distribution of an earthquake. Initially, it is assumed that modified Mercalli (MM) intensity values are directly related to the (A/T)z values of 1-Hz, Lg-wave ground motion. By comparison with the intensity values of a reference earthquake, magnitudes are calculated for 41 western and central United States earthquakes. Magnitudes of these earthquakes also are determined independently, in the conventional manner, using teleseismic P-wave amplitudes. Comparison of the two sets of magnitude values indicates that the assumed relation between 1-Hz, Lg-wave (A/T)z values and MM intensity does not hold exactly over the mb range of 4.0 to 6.2. An empirical equation is derived to adjust the mb values obtained from intensity data so that they agree with the teleseismic P-wave magnitudes. The method then is applied to estimate mb of some historical earthquakes which occurred prior to 1962. These include the set for which Kanamori and Jennings (1978) estimated ML from strong-motion accelerograms. Some noteworthy United States earthquakes also are considered. These include: the 1811 New Madrid earthquake for which mb is estimated to be 7.3; the 1886 Charleston, South Carolina earthquake, for which mb is estimated to be 6.6 to 6.9; the 1897 Giles County, Virginia earthquake, for which mb is estimated to be 5.8; the 1906 San Francisco, California earthquake, for which mb is estimated to be 6.8 to 7.1. The intensity-attenuation method cannot be used for estimating mb of all historical earthquakes because the intensity data are not always adequate. In some cases, however, the total felt area or the area enclosed by the Modified Mercalli IV isoseism can be determined. It was found that empirical equations relating mb to these areas, which were derived for central and northeastern United States earthquakes, also apply for events in the southeast. These empirical methods are used to estimate mb values for a set of historical Virginia earthquakes.

A New Concept of Intensity Data Area and Its Effect on the Parameter Determination of Historical Earthquakes

2020 ◽  
Vol 91 (5) ◽  
pp. 2685-2694 ◽  
Author(s):  
Jian Wang ◽  
Guoliang Lin
Keyword(s):  
Ming Dynasty ◽  
Population Distribution ◽  
Historical Earthquakes ◽  
Parameter Determination ◽  
Intensity Data ◽  
Historical Earthquake ◽  
Earthquake Parameters ◽  
Case Examples ◽  
The Government ◽  
High Tier

Abstract In ancient China, the government annals provided abundant historical earthquake records, which lasted more than 2000 yr. In some cases, the earthquake damage descriptions from the high-tier government annals are so concise that the specific place names were omitted, even the names of towns where the damage might have actually occurred. The intensity data point (IDP) was assigned to the capital town of the high-tier government, which might lead to large uncertainties in the historical earthquake parameters. A new concept of intensity data area (IDA) is proposed specifically to deal with this issue. An approach on how to convert the IDA to an IDP, based on nonseismological information, is described. In this process, we emphasize the effectiveness of field trips to investigate local features, such as natural environment, population distribution, historical administration zoning, and so forth. As case examples, two historical earthquakes in the Ming Dynasty are analyzed. The documentations of both earthquakes have a common problem, in that some damage was described with the name of the highest-tier local government (Fu); this led to the dispute about the parameter of historical earthquakes. With the proposed method, the IDA for Fu is successfully converted to an IDP at the suitable site. This is the key step to solve the dispute and reduce the parameter uncertainty. Our results have revealed that the parameters of both case earthquakes in the latest edition of the catalog (“The Catalog of Chinese Historical Strong Earthquakes (2300 B.C.–A.D. 1911)”) were wrong (Min et al., 1995). It is noteworthy that the latest edition of the catalog is currently in common use. To avoid the misuse of the catalog, it is better that the parameters in the catalog be restudied, especially for those labeled with large uncertainties.

Historical Earthquakes: New Intensity Data Points Using Complementary Data from Churches and Monasteries

2018 ◽  
pp. 103-116
Author(s):  
Gheorghe Marmureanu ◽  
Radu Vacareanu ◽  
Carmen Ortanza Cioflan ◽  
Constantin Ionescu ◽  
Dragos Toma-Danila
Keyword(s):  
Historical Earthquakes ◽  
Intensity Data ◽  
Data Points ◽  
Intensity Data Points
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