Frequently Asked Questions
If you have questions about what the DISS is or what we do, this is the place to start
- What is the meaning of the DISS version code?
- How frequently is the DISS updated?
- What version of the DISS should I use?
- Why does the "I" of the DISS acronym stand for "individual"?
- Why does DISS represent faults as rectangles or wide ribbons or depth contours whereas most geologic maps represent faults as lines?
- Why does DISS collect information about faults that generate earthquakes larger than magnitude 5.5 only?
- How do I cite the DISS in a scientific paper or technical report?
- What is the area coverage of the DISS?
- What is the difference between "compiler" and "contributor"?
The DISS version code is composed by three numbers separated by dots. The first number identifies different updates of database concept & design. The second number identifies signficant changes in the database structure while the database concept & design remain the same. The third number identifies a version of the database that has been updated only for what regards the fault parameters while the main database concept & design, and structure remain the same. Example: Version 3.2.0 incorporates subduction zones explicitly separated from crustal faults and other changes including the identification of compilers and contributors along with their affiliations or the date of creation of every database records. These details did not appear in versions 3.1.x. Differences between versions 3.1.x only regarded updates of fault parameters.
The database update is not regular because it depends on a number of factors, including availability of funding/resources, of new data, or also of new interpretations of old data. In the initial stage of DISS version 3 updates have been made available approximately once a year. Later versions, instead, are less frequent. Join our community or visit regularly this website to get the latest information about new database releases.
We recommend to always use the latest database release. Each new version is richer and more robust than previous versions. Occasionally, however, usage of previous version might be necessary to reproduce results of earlier experiments or to test ideas or approaches with knowledge available at an earlier time. Check the latest release, as well as older ones, in the data download page.
The DISS acronym was coined when the only category of seismogenic faults was that of "individual" sources (versions 1 and 2). At the time, the "I" stood for "Italian" also because the database was about potential seismogenic sources for the Italian territory. The DISS concept has later evolved, yet the acronym remained the same and still refers to the idea of "individual" source although today it reflects the content of the database only partially.
Faults are surfaces that cut the Earth outer shell at an angle. The DISS recognizes the need of always showing the third dimension of fault planes. This is important for several reasons, as for example, to understand whether two faults intersects at depth. To reduce the third dimension onto 2D maps, DISS shows the vertical projection of the fault surface onto the ground. Maps that show faults as lines only represent the fault intersection with the ground.
There exist a relation between fault size and earthquake magnitude. As a rule of thumb, the greater the fault the bigger the earthquake it can generate, and viceversa. Below magnitude 5.5 the size of the fault become smaller than the observation threshold.
If you are referring to the database concepts or the database as a whole you should cite the paper "Basili R., G. Valensise, P. Vannoli, P. Burrato, U. Fracassi, S. Mariano, M.M. Tiberti, E. Boschi (2008), The Database of Individual Seismogenic Sources (DISS), version 3: summarizing 20 years of research on Italy's earthquake geology, Tectonophysics, doi:10.1016/j.tecto.2007.04.014"; when referring to a specific dataset or data subset taken from a version of the database you should use the precise wording shown in its related download page
The DISS Working Group's priority is to make quality-checked information about seismogenic faulting available for an area that includes Italy and its surroundings. This priority stems primarily from the need of identifying potential sources of seismic shaking that may affect Italy. However, we also explore seismogenic faults outside this area because, for example, they may represent potential sources for tsunamis that can propagate across the Mediterranean Sea or they may be an important part of a geodynamic unit.
Each and every record (seismogenic source) of the DISS results from analysis of several geological and geophysical data. The compilers are those individual scientists that perform that analysis and format the results in a way that complies with the database requirements. Compilers are responsible for the compilation of the database and are the actual authors of database records. Contributors are those scientists that provide input, ideas, data or assist the analysis of data but do not participate in the process of incorporating a record in the database.