7. Drawing Inferences From Average Seismic Parameters

2018 ◽  
pp. 223-236
Keyword(s):  
Seismic Parameters

scholarly journals Statistics of seismicity to investigate the Campi Flegrei caldera unrest

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Tramelli ◽  
C. Godano ◽  
P. Ricciolino ◽  
F. Giudicepietro ◽  
S. Caliro ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Central Area ◽  
Seismic Energy ◽  
Progressive Increase ◽  
Campi Flegrei ◽  
Cumulative Number ◽  
Seismic Parameters ◽  
Seismicity Rate ◽  
Seismic Catalogue ◽  
Vertical Ground

AbstractThe knowledge of the dynamic of the Campi Flegrei calderic system is a primary goal to mitigate the volcanic risk in one of the most densely populated volcanic areas in the world. From 1950 to 1990 Campi Flegrei suffered three bradyseismic crises with a total uplift of 4.3 m. After 20 years of subsidence, the uplift started again in 2005 accompained by a low increment of the seismicity rate. In 2012 an increment in the seismic energy release and a variation in the gas composition of the fumaroles of Solfatara (in the central area of the caldera) were recorded. Since then, a slow and progressive increase in phenomena continued until today. We analyze the INGV - Osservatorio Vesuviano seismic catalogue of Campi Flegrei from 2000 to 2020 in order to look for any variation in the seismic parameters and compare them with geochemical monitored ones. A remarkable correlation between independent variables of earthquake cumulative number, CO/CO2 values and vertical ground deformation reveals a likely common origin. Moreover the correlation between all the variables here analysed enlightens that the same origin can cause the temporal behavior of all these variables. We interpret the seismological, geochemical and geodetic observable in terms of the injection of magmatic fluids into the hydrothermal system or its pressurization.

An analysis of some local earthquake phases originating near the afar triple junction

1971 ◽  
Vol 61 (4) ◽  
pp. 1061-1071
Author(s):  
R. C. Searle ◽  
P. Gouin
Keyword(s):  
Travel Time ◽  
Red Sea ◽  
Triple Junction ◽  
Addis Ababa ◽  
Northern Ethiopia ◽  
Seismic Velocities ◽  
Low Velocity ◽  
Seismic Parameters ◽  
Local Earthquake ◽  
Ray Paths

abstract A study of Pn, Sn and Lg phases from 86 earthquakes which have occurred within 12.4° of WWSS station AAE is presented. Travel-time curves for each phase have been determined, and the corresponding seismic velocities have been deduced from them. Velocities of 7.95 km/sec and 4.29 km/sec were found for Pn and Sn respectively. Two different Lg velocities were found: 3.50 km/sec for ray paths between Uganda and Addis Ababa, and 3.73 km/sec for ray paths in the Red Sea and northern Ethiopia. The travel-time curves also allow an upper limit of 48 km to be placed on the crustal thickness under AAE. Regional variations in the efficiency of propagation of Sn and Lg are discussed. Efficient propagation of Lg from epicenters near the center of the Red Sea suggests that not all of the Red Sea floor is pure oceanic crust. Sn is not propagated across northern Afar, suggesting that a gap occurs in the lithosphere there, but it is propagated efficiently across much of southern Afar. Finally, the seismic parameters deduced here indicate the existence of a widespread region of high temperature, low velocity, low density upper-mantle material underlying the Afar triple junction and the surrounding regions.

scholarly journals The influence of geomagnetic and seismic parameters on mortality from cardiovascular pathologies in the Shamakhi Region of the Republic of Azerbaijan

2021 ◽  
pp. 6-12
Author(s):  
L. G. Afandieva
Keyword(s):  
Heart Failure ◽  
Age Groups ◽  
Close Correlation ◽  
Seismic Process ◽  
Case Histories ◽  
Chi Square ◽  
Seismic Parameters ◽  
Cardiovascular Pathologies ◽  
The Republic ◽  
The Relationship

Aim. Study of the dependence of mortality from CVD on helio-seismic indicators in the Shamakhi region of the Republic of Azerbaijan.Materials and methods. 352 case histories of patients who died in 2013 from various diseases were reviewed. The relationship was established between the number of deaths, their causes, distribution by sex and age with the magnitude of earthquakes, the depth of the epicenter and seismological activity by months. The data obtained were statistically processed using the Statistica 12.0 for Windows software package (Statsoft Inc., USA). To establish correlations, Pearson Chi-Square Tests was calculated, the results were considered reliable at p <0.05.Results. Statistically significant (p <0.001) more deaths were observed at the age of 80-89 years in men, and at the age of 70-79 years in women. Also, the relationship between mortality and the depth of the seismic process and the magnitude of the earthquake was established, in particular, the greatest number of deaths was observed at a depth of the seismic process <10 km and with a magnitude of 1.1-2.0 ml. In all months, the number of deaths was higher with a magnitude of 1.1-2.0 Ml. Statistically significant (p <0.005) was the fact that the nosology of the studied diseases was dependent on the age of the patients. Thus, a greater number of deaths in all age groups accounted for heart failure. A statistically significant (p <0.005) dependence of the depth of the seismic process on the month of death of patients was established, in particular, for all months, deaths coincided with the depth of the process less than 10 km. At the age of 40-70 years, a significantly greater number of deaths were from heart failure in men, and from 70 years and above in women.Conclusion. Thus, there is a close correlation between geomagnetic changes and mortality from CVD, which is realized in the form of an increase in the frequency of cases and deaths, and the number of these cases increases with the age of patients and changes in the magnitude and depth of the earthquake.

The Amethyst Field, Blocks 47/8a, 47/9a, 47/13a, 47/14a, 47,15a, UK North Sea

1991 ◽  
Vol 14 (1) ◽  
pp. 387-393 ◽  
Author(s):  
C. R. Garland
Keyword(s):  
North Sea ◽  
Reservoir Quality ◽  
Geological Model ◽  
Gas Field ◽  
Seismic Parameters ◽  
Recoverable Reserves ◽  
High Production ◽  
Sandstone Formation ◽  
Phased Development ◽  
Overlying Strata

AbstractThe Amethyst gas field was discovered in 1970 by well 47/13-1. Subsequently it was appraised and delineated by 17 wells. It consists of at least five accumulations with modest vertical relief, the reservoir being thin aeolian and fluviatile sandstones of the Lower Leman Sandstone Formation. Reservoir quality varies from poor to good, high production rates being attained from the aeolian sandstones. Seismic interpretation has involved, in addition to conventional methods, the mapping of several seismic parameters, and a geological model for the velocity distribution in overlying strata.Gas in place is currently estimated at 1100 BCF, with recoverable reserves of 844 BCF. The phased development plan envisages 20 development wells drilled from four platforms, and first gas from the 'A' platforms was delivered in October 1990. A unitization agreement is in force between the nine partners, with a technical redetermination of equity scheduled to commence in 1991.

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