Geography Reference
In-Depth Information
Figure 39. a) Gravity anomaly map of Tohoku earthquake area according to [72] and
ENDDB tools. b) The vertical section AA of the gravity anomaly. White circle (a) and
black arrow (b) show the Tohoku epicenter. The scale shows gravity in mGal.
C
ONCLUSION
The geoinformation system ENDDB (Earth's Natural Disasters Database)
is an important tool to study natural disasters, such as earthquakes or impact
events, using records of the respective catalogs. The GIS system has a user-
friendly easy-to-run interface, detailed geographical databases for the whole
Earth and its regions, and ample databases of seismological and impact
structure parameters. With its mathematical support, ENDDB can plot
frequency dependences of magnitudes or sizes (crater diameters) of events
from various samples, as well as other distributions of integrated parameters in
time and space, or with respect to one another. Necessity of using geological
and geophysical parameters (gravity field, faults, etc.) for analysis of data from
both EC and EISC (Catalogs of earthquakes and Earth's impact structures),
has been a prerequisite for creating the combined system of ENDDB from its
two prototypes, GIS EEDB (Expert earthquake database) and GIS EISC.
Introducing the gravity information into ENDDB expands largely its
application; specifically, it has made possible detecting new morphological
features characteristic of impact structures. It is especially important to find
additional morphological indicators for the lack of absolutely reliable
diagnostic features of extraterrestrial origin, even for the structures whose
impact nature has been confirmed by rich shock-explosive evidence. This lack
of certainty has given reason to the opponents of the impact genesis of ring
structures to continue vigorous debates in the literature. Note that the
asymmetry of different geomorphic characteristics of impact craters, and, in
