The New Zealand Active Faults Database

Figures & data

Figure 1. Map of New Zealand highlighting the active faults presented in the NZAFD250 view (red). Locations of photo images in Figure 2 are identified with white stars. The map highlights three areas that are discussed in more detail in Figures 3 and 4.

Table 1. Summary of GIS attributes developed for the NZAFD250; refer to Langridge et al. (2014a) for detailed definitions. The five fault parameter attributes displayed in the online version are shaded.

Field (units)	Type	Brief description	Example attributes
ACCURACY	Limited text	Location accuracy of a fault trace on the ground surface at 1:250,000 scale	Accurate, approximate or uncertain
AFDB_ID	Integer	Unique GIS identifier number of a fault trace	e.g. 11224
BIB_ID	Integer	Unique GNS Science bibliographic number for a published paper	e.g. 12334
DIP (°)	Limited text	The angle that the fault plane dips from horizontal (measured or inferred)	Shallow (≤30), low (30 to ≤50), moderate (50 to ≤70), steep (>70)
DIP_DIRN	Limited text	The compass direction towards which the fault plane dips	N, NE, NW, E, W, SE, SW, S
DISPLACEMENT (m)	Limited text	The average net displacement caused by an individual fault movement	Minor (≤1), moderate (1 to ≤5), major (≥5)
DOM_SLIPTYPE	Limited text	The dominant sense of fault slip	Dextral, sinistral, reverse, normal
DOWN_QUAD	Limited text	The compass direction of the downthrown side (of a fault) relative to the fault trace	N, NE, NW, E, W, SE, SW, S
LAST_EVENT^a	Limited text	The timing or age of the last surface-rupturing event on a fault	Historical, millennial, Holocene, Late Pleistocene
LINE_ACCURACY (m)	Integer	The scale at which the fault is mapped and the uncertainty to which it can be reliably used	250
LINE_SOURCE	Text	The origin of the line depicting a fault	e.g. QMAP, NZAFD
NAME	Text	The name given to an active fault	e.g. Wellington Fault
REC_INTERVAL^b	Limited text	The average recurrence interval expressed in six classes, representing the estimated average repeat time between ground surface rupturing earthquakes on a fault	Roman numerals; classes I-VI as used in the MfE Guidelines^b
SECTION	Text	The name given to a distinct geomorphic section of an active fault	e.g. Wellington-Hutt Valley Section
SLIP_RATE (mm a^–1)	Limited text	The net rate of fault movement over geological timescales	Very low (≤0.2), low (0.2 to ≤1), moderate (1 to ≤5), high (5 to ≤10), very high (≥10)
SUB_SLIPTYPE	Limited text	The subordinate sense of fault movement or slip (if any)	Dextral, sinistral, reverse, normal

^aHistorical, since 1840 AD; millennial, pre-1840 to ≤ 1000 yr BP; Holocene, > 1000 to ≤ 11,700 yr BP; Late Pleistocene, > 11,700 to ≤ 125,000 yr BP.

^bI ≤ 2000 yr; II > 2000 to ≤ 3500 yr; III > 3500 to ≤ 5000 yr; IV > 5000 to ≤ 10,000 yr; V > 10,000 to ≤ 20,000 yr; VI > 20,000 to ≤ 125,000 yr.

Figure 2. Oblique aerial photograph examples of active faults in New Zealand; traces highlighted by arrows. A, The Hanmer Fault in north Canterbury at the foot of the Hanmer Range. B, The 1987 surface rupture trace of the Edgecumbe Fault, Bay of Plenty. C, The 2010 surface rupture trace of the Greendale Fault, Canterbury. D, Closely spaced normal faults in the northern part of the Taupo Rift (Photographs: A, B, D: DL Homer, GNS Science; C: R Jongens, GNS Science).

Figure 3. Examples of how to view the NZAFD250 data using a GIS or online. A, Selection of faults by style (DOM_SLIPTYPE) in the Hawke's Bay region (within white line). B, Selection of faults that have produced surface rupture (LAST_EVENT) in the historical period (red) among active faults of the central South Island (black). Locations of photo images in Figure 2 are identified with white stars.

Figure 4. Examples of mapping closely spaced faults in the Bay of Plenty region in the NZAFD250. A, Faults in the North Island Shear Belt are broadly spaced compared to the Taupo Rift. B, Faults to the southwest of Lake Tarawera (inset) are very closely spaced but were able to be mapped at a detail that is consistent with a scale of 1:250,000. Locations of photo images in Figure 2 are identified by white stars.

Figure 5. Using the Greendale Fault, Canterbury to highlight different views of active fault data sources. A, A view from field observations and LiDAR mapping at a scale of c. 1:5000. B, A simplified view for use at 1:250,000. C, A further simplified view for modelling purposes.

Langridge RM, Ries WF, Litchfield NJ, Van Dissen RJ, Villamor P. 2014a. The 1:250,000 Active Faults Database of New Zealand: database description and data dictionary. GNS Science Report 2014/11. Lower Hutt: GNS Science.

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