Geologic faults in Nicaragua
The geologic faults are expression of the continuous movement in which is the Earth crust. The shock of the tectonic plates Cocos and the Caribbean generates great tensions in the crust and the different blocks from the same ones tend to comply to each other. The movements in the faults are the cause of the earthquakes. The existence of faults in all the territory of Nicaragua agrees with the possible occurrence of earthquakes in all Nicaragua.
Geologic faults in Nicaragua
Geologic faults of Managua
The geologic faults and lineamientos including in the Map N° 13: Geologic faults of Managua, have the following geometric parameters according to the Nº26 Picture.
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Nº26 picture
Denomination of geologic elements |
Length overall |
|
Verified faults (by geologists) |
106 km |
|
Supposed faults (known by aerial photos) |
69 km |
|
Subtotal faults |
175 km |
|
Lineamientos main (Lineamientos that is identified in aerial photos, that probably are faults) |
334 km |
|
Lineamientos secondary (Lineamientos that is identified in aerial photos that are smaller possibly faults) |
47 km |
|
Subtotal lineamientos |
381 km |
|
TOTAL |
556 km |
From this it is that the density (length by area) of the total of faults is of 0,69 km-1, and the density of the total of the faults and lineamientos is of 2,2 km-1, considering that the Area of Study has a 252 extension of km2
If one assigns to the faults and lineamientos a “runner of security” of 50 meters of wide to each side of the fault, this runner occupies 56 a total area of km2. This area could be considered as the zone of high threat by superficial fallamiento. With this definition the zone of high threat occupies 22% of the study area. If wide one of the security runner is applied another, the area of the zone of high threat varies proportionally.
The verified faults cross the superficial estratigráficas layers, that is to say, youngest, and by this they must be considered active (activity verified in the last 11.000 years, that is to say, in the Holoceno). One assumes that also the supposed faults and photo-lineamientos represent active faults, but this could not be verified in the field is by limitations of the time or not to count on a suitable methodology (for example, adapted equipment of geophysical).
Given to the high speed of formation of new layers (for example, by volcanic ash fall or sedimentation) all the active geologic faults in Managua they do not have to present/display superficial fallamiento in the depths of 3 to 4 meters, that are normally attainable with the geologic trench method.
The areas, including some parts of the old center of Managua, where the map does not present/display geologic faults or lineamientos, are not necessarily free of these. It can be that certain areas sufficiently have still not been studied with suitable methods to detect these geologic structures. Really, still there is zones with few knowledge on the existence or trajectory of the faults (“white areas”).
