Using the Qfaults shapefile as the spatial repository of strain data, an ArcView 3.X extension FSA.avx was developed to calculate the average strain rate tensor of these faults. FSA.avx calculates the shear tensor, dilation tensor, and second invariant of strain and presents the results in ESRI grid format.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Great Basin
Center for Geothermal Energy
Contact_Person:
Richard Zehner
Contact_Position: Research Scientist/Assistant
GIS Specialist
Contact_Address:
Address_Type: mailing and physical
address
Address: MS 172, University of
Nevada, Reno
City: Reno
State_or_Province:
NV
Postal_Code: 89557
Country: USA
Contact_Voice_Telephone:
775-784-7055
Contact_Facsimile_Telephone:
775-327-5801
Contact_Electronic_Mail_Address:
zehner@unr.edu
Hours_of_Service: 8-5 M-F Pacific
Time
Compilers and cooperators are listed on the web page (<http://earthquake.usgs.gov/qfaults/contrib.html>). Compilers are those who described faults or folds for the database. Cooperators are those who assisted with the development of digital fault data (traces), the database structure, or the geographical information system (GIS) interfaces.
The most recent effort began in 1990 in support of the International Lithosphere Program (ILP), which formed Working Group II-2. Its main objective was to compile a World Map of Active Faults (Vladimir Trifonov, chairman). In 1992, the USGS agreed to help compile maps and fault descriptions for countries in the Western Hemisphere (North, Central, and South America, as well as Australia and New Zealand). This work continues to date, with many of the compilations for Central and South America countries having been published.
In 1993, the U.S. Geological Survey began developing a database for Quaternary faults and folds for the United States in earnest, largely supported by NEHRP but with significant support from many State surveys. This product is more robust than the ILP products, mainly owing to the vast amount of data that has become available within the U.S. in the past 20-30 years and the importance that this data plays in regional and national seismic-hazard assessments (Petersen and others, 1996; Frankel and others, 1996).
For this compilation, we have limited our compilation to synthesis of published literature relevant to the United States. Our definition of published literature includes typical sources (journals and maps), as well as M.S. theses and Ph.D. dissertations, governmental contract reports (which includes many NEHRP-sponsored studies), abstracts, and open-file (preliminary) reports. We generally do not cite unpublished field mapping, field notes, and other gray-literature reports that are not generally available to the public. The data presented in the compilation are extensively referenced using the standard USGS reference style, with the exception of attaching a unique number to each cited reference for convenience. This numeric identifier allows us to clearly cite multiple-same year publications for authors.
For a complete list of contributors, see <http://earthquake.usgs.gov/qfaults/contrib.html>
- 1. Rake Calculation (first operation)
If sliptype = 2 (thrust/reverse) then rake = 90
If sliptype = 3 (normal) then rake = -90
If sliptype = 1 and slipsense = right lateral then rake = 180
If sliptype = 1 and slipsense = left lateral then rake = 0
If sliptype is null (now assigned ‘9’) then look at Slipsense
If slipsense is ‘normal’ then rake = -90
If ‘reverse’ then rake = 90
If ‘right lateral’ then rake = 180
If ‘left lateral’ then rake = 0
If slipsense is ‘incomplete’ then rake = -90
2. Slip rate calculation
Use calculated slip rate from spreadsheets where available
If not calculated slip rate:
And Rate <0.2, then slip rate = 0.1
And Rate is 0.2-1, then slip rate = 0.5
And Rate is 1-5, then slip rate = 2.5
And Rate is >5, then slip rate = 12
3. Uncertainty calculation
Use uncertainty specified in spreadsheets (CA only) where available
If not available, then uncertainty = 50% of slip rate
4. Slip Dip Calculation
Use spreadsheet values where available.
When these vales not available:
If sliptype =1, then dip = 90
If sliptype =2, then dip = 45
If sliptype =3, then dip = 60
If sliptype data is unavailable, then use slipsense
If slipsense is ‘normal’ then dip = 60
If ‘reverse’ then dip = 45
If ‘right lateral’ then dip = 90
If ‘left lateral’ then dip = 90
If slipsense is ‘incomplete’ then dip = 60
- Lambert_Conformal_Conic:
- Standard_Parallel: 33.000000
- Standard_Parallel: 45.000000
- Latitude_of_Projection_Origin: 0.000000
- False_Easting: 0.000000
- False_Northing: 0.000000
- Planar_Distance_Units: Meters
Geodetic_Model:
- Ellipsoid_Name: Clarke 1866
- Semi-major_Axis: 6378206.4000000
- Denominator_of_Flattening_Ratio: 294.98 Top
>First digit: fault visibility code
>1 = exposed
>2 =
concealed
>3 = inferred
>
>Second digit: fault age
code
>1 = historic
>2 = Holocene < 15,000 years
>3
= late Quaternary < 130,000 years
>4 = mid to late Quaternary
< 750,000 years
>5 = Quaternary < 1,600,000 years
>6 =
class B
>7 = unknown
>0 = unknown
>
>Third
digit: fault slip rate code
>1 = >5 mm/year
>2 =
1-5
>3 = .2 - 1
>4 = < .2 mm/year