Newly observed, deep slow slip events at the central Hikurangi margin, New Zealand: Implications for downdip variability of slow slip and tremor, and relationship to seismic structure
Article first published online: 29 OCT 2013
©2013. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 40, Issue 20, pages 5393–5398, 28 October 2013
How to Cite
2013), Newly observed, deep slow slip events at the central Hikurangi margin, New Zealand: Implications for downdip variability of slow slip and tremor, and relationship to seismic structure, Geophys. Res. Lett., 40, 5393–5398, doi:10.1002/2013GL057682., and (
- Issue published online: 18 NOV 2013
- Article first published online: 29 OCT 2013
- Accepted manuscript online: 11 OCT 2013 01:46AM EST
- Manuscript Accepted: 8 OCT 2013
- Manuscript Revised: 7 OCT 2013
- Manuscript Received: 16 AUG 2013
- slow slip events;
- New Zealand;
 We present previously undocumented deep (25–45 km depth), moderate-duration (2–3 months) slow slip events (SSEs) directly downdip of known shallow (<15 km depth), short-term (2–3 weeks) SSEs at the central Hikurangi margin, New Zealand. The moderate-duration SSEs produce 2–6 mm of horizontal displacement at continuous Global Positioning System stations in 2006 and 2008, similar to Cascadia SSEs. They involve 2–5 cm of slip over ~5000 km2 of the subduction interface. Tremor occurs just downdip of the deep SSE source area. We also present results from a large, shallow (<12 km) SSE in 2013 just updip of the 2006/2008 SSEs. The location of deep SSEs between shallow, short-term SSEs and tremor indicates strong downdip variation of subduction interface slip behavior at central Hikurangi. The deep SSEs occur where Qp and Vp/Vs data suggest an accumulation of fluid-rich underplated sediment at the interface, consistent with the idea that SSEs occur under high fluid pressure.