Analisi critica su le profondità ipocentrali.
| Autor: | M. PERONACI, L. MARCELLI |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1979 |
| Předmět: | |
| Zdroj: | Annals of Geophysics, Vol 32, Iss 1, Pp 263-288 (1979) |
| Druh dokumentu: | article |
| ISSN: | 1593-5213 2037-416X |
| DOI: | 10.4401/ag-4737 |
| Popis: | The aim of this study is to point out the difficulties in the analyticaldetermination of hypocentral depth h and the consequent uncertainty inits reliability.The former attempt was realized at world-wide level (december 1964),the latter in the Mediterranean Area (19 reigons, accordingly to the divisionproposed by Flin, Engdal, Hill, 1974).We considered hypocentral data of the earthquakes occurred in thatarea during the 1964-1974 decade, with a great care to the h values andtheir standard deviations.First we pointed out the depth features of every region: afterwardswe looked into the standard deviations (E) and their respective h valuesData analysis suggested us to calculate a series of exponential functionsE = P h"- showing standard deviations as a function of focal depth;every region is characterized by a and 3 coefficients calculated by a least squares fit.We analysed results and also made an attempt to explain the standarddeviations scatter. We also made an attempt by only Italian earthquakesdata (ioining the four sections Northern, Central, Southern Italy, andSicily), and we calculated the t = f(h) function.Both the world-wide analysis and the Mediterranean one pointed outsome interesting elements.— Focal depth data, even if joined with their standard deviations,are very unrealiable particularly for crustal earthquakes; in that casestandard deviations often are too large and focal depth lose their physicalmeaning.— In the upper mantle the data are more reliable.Obviously the choise of the travel-times used to calculate focal depthinfluences data reliability, particularly in the most heterogeneous layersin the crust. |
| Databáze: | Directory of Open Access Journals |
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