Page 9 - gt1503-04

are important. Investigations addressing the dynamic geomorphic
responses of urban rivers and coastal plains to relative sea-level
rise, shoreline retreat, groundwater responses, liquefaction,
subsidence, and coastal aquifer resources are all urgently required.
In parallel with these scientific considerations, there also needs to
be a focus on how current policies, planning, and socio-economic
contexts will influence trajectories of urban form, and to what
degree these will influence the exposure of current and future
communities to continued flooding and sea-level rise.
The anthropogenic intervention of long-term geologic processes
that previously enabled sediment aggradation to rebuild topog-
raphy in this area means that subsidence will continue to domi-
nate the topographic evolution of Christchurch. Similar scenarios,
where prograding sediment has been diverted from subsiding
areas, are likely to plague coastal settlements worldwide. Strong
earthquakes sourced from previously unidentified and/or blind
faults and their impacts on flood and relative sea levels add to the
myriad of short- to long-term challenges facing coastal environ-
ments throughout the world.
Future investigations of the impacts of relative sea-level rise on
coastal populations should consider the role of earthquakes,
including those that may be sourced from unknown and/or prox-
imal faults, in reshaping coastal topography and thus influencing
the dynamics of coastal and flood hazards. As shown here, this is
particularly important for densely populated, low-lying, and
tectonically active regions built upon youthful and liquefiable
alluvial and marine sediments.
ACKNOWLEDGMENTS
We thank the New Zealand Earthquake Commission for research
capability funding and for provision of LiDAR data. These and other
data are available on the Canterbury Geotechnical Database (https://
canterburygeotechnicaldatabase.projectorbit.com/). We also thank
Environment Canterbury and the New Zealand Ministry of Business,
Innovation and Employment (MBIE contract UOCX0902) for funding
analyses of the Avon-Heathcote Estuary.
REFERENCES CITED
Aerts, J.C.J.H., Botzen, W.J.W., Emanuel, K., Lin, N., and De Moel, H., 2014,
Evaluating flood resilience strategies for coastal megacities: Science, v. 344, Cubrinovski, M., Hughes, M., Bradley, B., Noonan, J., Hopkins, R., McNeill, S.,
p. 473–475, doi: 10.1126/science.1248222.
Basher, L.R., Hicks, D.M., McSaveny, M.J., and Whitehouse, I.E., 1988, The
lower Waimakariri River floodplain: A geomorphological perspective:
A report for North Canterbury Catchment Board, 33 p.
Beavan, J., Samsonov, S., Motagh, M., Wallace, L., Ellis, S., and Palmer, N.,
2010, The Darfield (Canterbury) Earthquake: Geodetic observations and
preliminary source model: Bulletin of the New Zealand Society for
Earthquake Engineering, v. 43, p. 228–235.
Beavan, J., Fielding, E., Motagh, M., Samsonov, S., and Donnelly, N., 2011,
Fault location and slip distribution of the 22 February 2011 MW 6.2
Christchurch, New Zealand, Earthquake from geodetic data: Seismological
Research Letters, v. 82, p. 789–799, doi: 10.1785/gssrl.82.6.789.
Beavan, J., Levick, S., Lee, J., and Jones, K., 2012a, Ground displacements and dila-
tional strains caused by the 2010–2011 Canterbury earthquakes: GNS Science
Consultancy Report 2012/67.59, https://canterburygeotechnicaldatabase
.projectorbit.com (last accessed 12 Dec. 2014).
Beavan, J., Motagh, M., Fielding, E.J., Donnelly, N., and Collett, D., 2012b, Fault
slip models of the 2010–2011 Canterbury, New Zealand, earthquakes from
geodetic data and observations of postseismic ground deformation: New
Zealand Journal of Geology and Geophysics, p. 37–41, doi: 10.1080/
00288306.2012.697472.
Bech, D., Cordova, P., Tremayne, B., Tam, K., Weaver, B., Wetzel, N., Parker,
W., Oliver, L., and Fisher, J., 2014, Common structural deficiencies
identified in Canterbury buildings and observed versus predicted GSA TODAY | www.geosociety.org/gsatoday/
performance: Earthquake Spectra, v. 30, p. 335–362, doi: 10.1193/
021513EQS028M.
Bradley, B.A., 2012, Strong ground motion characteristics observed in the
4 September 2010 Darfield, New Zealand earthquake: Soil Dynamics and
Earthquake Engineering, v. 42, p. 32–46, doi: 10.1016/j.soildyn.2012.06.004.
Bradley, B.A., and Cubrinovski, M., 2011, Near-source strong ground motions
observed in the 22 February 2011 Christchurch Earthquake: Seismological
Research Letters, v. 82, no. 6, p. 853–865, doi: 10.1785/gssrl.82.6.853.
Bradley, B.A., Quigley, M.C., Van Dissen, R.J., and Litchfield, N.J., 2014, Ground
motion and seismic source aspects of the Canterbury Earthquake Sequence:
Earthquake Spectra, v. 30, p. 1–15, doi: 10.1193/030113EQS060M.
Briggs, R.W., Sieh, K., Meltzner, A.J., Natawidjaja, D., Galetzka, J., Suwargadi,
B., Hsu, Y.-J., Simons, M., Hananto, N., Suprihanto, I., Prayudi, D.,
Avouac, J.-P., Prawirodirdjo, L., and Bock, Y., 2006, Deformation and slip
along the Sunda megathrust in the great 2005 Nias-Simeulue earthquake:
Science, v. 311, p. 1897–1901, doi: 10.1126/science.1122602.
Brock, J.C., and Purkis, S.J., 2009, The emerging role of LiDAR remote sensing
in coastal research and resource management: Journal of Coastal
Research, Special Issue 53, p. 1–5, doi: 10.2112/SI53-001.1.
Brown, L.J., and Weeber, J.H., 1992, Geology of the Christchurch Urban Area:
GNS Science, scale 1:25:000, 104 p.
Canterbury Regional Council, 1993, Avon and Heathcote catchment, rivers and
estuary: Issues and options for managing the Heathcote River floodplain:
Canterbury Regional Council Report R93(1), 43 p.
Canterbury Regional Council, 1997, Avon River: Issues and options for
managing the Avon River floodplain: Canterbury Regional Council
Report R97(1), 41 p.
Cazenave, A., Dieng, H., Meyssignac, B., Von Schuckmann, K., Decharme, B.,
and Berthier, E., 2014, The rate of sea-level rise: Nature Climate Change,
v. 4, p. 358–361, doi: 10.1038/nclimate2159.
CCC, 2014, Flood extent models, Christchurch city council flood modeling
data, hosted by the Canterbury Earthquake Recovery Authority: http://
maps.cera.govt.nz/advanced-viewer/?Viewer=Ccc-Floor-Levels (last
accessed 12 Dec. 2014).
Center for Advanced Engineering, 1995, Risks and Realities—A Multidisciplinary
Approach to the Vulnerability of Lifelines to Natural Hazards: Report of
the Christchurch Engineering Lifelines Group: Christchurch, New
Zealand, University of Canterbury, Center for Advanced Engineering, 312 p.
Cox, S.C., Rutter, H.K., Sims, A., Manga, M., Weir, J.J., Ezzy, T., White, P.A.,
Horton, T.W., and Scott, D., 2012, Hydrological effects of the MW 7.1
Darfield (Canterbury) earthquake, 4 September 2010: New Zealand
Journal of Geology and Geophysics, v. 55, no. 3, p. 231–247, doi: 10.1080/
00288306.2012.680474.
and English, G., 2014a, Performance of horizontal infrastructure in
Christchurch City through the 2010–2011 Canterbury Earthquake
Sequence: University of Canterbury, Civil & Natural Resources
Engineering Research Report 2014-02, March 2014, 129 p.
Cubrinovski, M., Hughes, M., and O’Rourke, T., 2014b, Impacts of liquefaction
on the potable water system of Christchurch in the 2010–2011 Canterbury
(NZ) earthquakes: Journal of Water Supply: Research & Technology–Aqua,
v. 63, p. 95–105, doi: 10.2166/aqua.2013.004.
Cubrinovski, M., Winkley, A., Haskell, J., Palermo, A., Wotherspoon, L.,
Robinson, K., Bradley, B., Brabhaharan, P., and Hughes, M., 2014c,
Spreading-induced damage to short-span bridges in Christchurch:
Earthquake Spectra, v. 30, p. 57–83, doi: http://dx.doi.org/10.1193/
030513EQS063M.
Dixon, T.H., Amelung, F., Feretti, A., Novali, F., Rocca, F., Dokka, R., Sella,
G., Kim, S.-W., Wdowinski, S., and Whitman, D., 2006, Subsidence and
flooding in New Orleans: Nature, v. 441, p. 587–588, doi: 10.1038/
441587a.
Downes, G., and Yetton, M., 2012, Pre-2010 historical seismicity near
Christchurch, New Zealand: The 1869 MW 4.7–4.9 Christchurch and 1870
MW 5.6–5.8 Lake Ellesmere earthquakes: New Zealand Journal of Geology
and Geophysics, v. 55, no. 3, p. 199–205, doi: 10.1080/00288306
.2012.690767.
9