The isoseismal lines shown in Fig. 41 are not to be regarded as drawn with great accuracy; for there is no marked separation between the tests corresponding to the different degrees of the scale of intensity. ❋ Charles Davison (1899)
It is similar in form to the second isoseismal, reaching as far as Estepone to the south-west, ❋ Charles Davison (1899)
_ -- Within the third isoseismal line Mallet made altogether 177 measurements of the direction of the wave-path at 78 places. ❋ Charles Davison (1899)
On the map in Fig. 60, the continuous curves represent isoseismal lines corresponding to the degrees 8, 7, 6, 5, and 4 of the ❋ Charles Davison (1899)
The isoseismal 8, which is the most accurately drawn of the series, is an elongated oval, 40 miles long, 23 miles broad, and containing an area of 724 square miles. ❋ Charles Davison (1899)
It will be seen that they differ considerably in form, but at the same time they present certain points of agreement, such as the east and west elongation of the meizoseismal area, and the great extension of the two outer isoseismals towards the west and south-west The greatest difference is to be found in the eastern portion of the third isoseismal, which, according to the ❋ Charles Davison (1899)
Making use of these observations, Professor Omori has drawn two isoseismal lines within the central district, which are shown in Fig. 44. ❋ Charles Davison (1899)
The resistance offered by the Sierra Nevada to the propagation of the earth-waves is shown in the former map by the approximation of the first and second isoseismals at the east end, and in the latter by the great bay in the third isoseismal line. ❋ Charles Davison (1899)
A third isoseismal (not shown in the map) encloses the district in which the shock was "very strong," or just capable of producing cracks in the walls of houses. ❋ Charles Davison (1899)
The isoseismal 7, which includes places where the shock was strong enough to overthrow ornaments, vases, etc., is also very nearly an ellipse, whose axes are 80 and 56 miles in length, and whose area is ❋ Charles Davison (1899)
Ischian earthquake of 1881, investigation of, 50; isoseismal lines and disturbed area, 51; position of epicentre, 52; depth of focus, 54; nature of shock, 55; after-shocks, 56; origin of, 70; bibliography, 73 ❋ Charles Davison (1899)
The first isoseismal is about 2-1/2 miles long, 1-1/2 miles broad, and ❋ Charles Davison (1899)
Mallet himself recognised that these facts required explanation, and he suggested that the situation and character of the towns were in part responsible for their ruin, and the physical structure of the country for the course of the isoseismal lines. ❋ Charles Davison (1899)
The next isoseismal (2) includes the places in which some buildings were ruined, but not as a rule completely, and in which there was no loss of life. ❋ Charles Davison (1899)
In traversing this range, the shock lost a great part of its strength, while it continued to be felt severely along its eastern foot, thus giving rise to the south-westerly extension of the third isoseismal in Fig. 20, and, though to a less extent, that of the second in Fig. 19. ❋ Charles Davison (1899)
Mercalli is probably more trustworthy, it is interesting to compare his isoseismal lines with those obtained by his French colleagues, which are reproduced in Fig. 20. ❋ Charles Davison (1899)
The isoseismal 6 is 105 miles long, 87 miles wide, and contains 7,300 square miles; and the isoseismal 5, 157 miles long, 143 miles wide, and about 17,000 square miles in area. ❋ Charles Davison (1899)
Again, in slight earthquakes, such as the Cornwall earthquake of April 1, 1898, [83] the curves of equal sound intensity, while their axes are parallel to those of the isoseismal lines, are displaced laterally with respect to these curves, owing to the arrival of the strongest sound-vibrations from the upper margin of an inclined seismic focus. ❋ Charles Davison (1899)
If the meizoseismal area had been a thickly populated one, the evidence of ruined and damaged houses would have provided materials for the construction of isoseismal lines surrounding the two epicentres. ❋ Charles Davison (1899)
The land area disturbed by the earthquake and the different isoseismal lines are shown in Fig. 41. ❋ Charles Davison (1899)
