Magnitude 7.0 Earthquake of Christchurch, New Zealand

Location	43.530°S, 172.120°E
Depth	5 km (3.1 miles) set by location program
Region	SOUTH ISLAND OF NEW ZEALAND
Distances	45 km (30 miles) W of Christchurch, New Zealand 200 km (125 miles) SSE of Westport, New Zealand 290 km (180 miles) NNE of Dunedin, New Zealand 330 km (205 miles) SW of WELLINGTON, New Zealand
Time	Saturday, Sep 04, 2010, 04.36.46 AM Local time (UTC+12)
Parameters	NST (Number of station reporting Primary and Secondary wave for this earthquake) 374 Nph (Number of Primary and Secondary wave observation used to compute hypocenter location) 374 Dmin (Horizontal distance from from the epicenter to the nearest station) 88.7 km Rmss (the difference between predicted arrival time and observed arrival time of the earthquake) 0 sec Gp (The largest azimuthal gap between azimuthally adjacent stations) 18° M-type=centroid moment magnitude (Mw), Version=9
Source	Institute of Geological and Nuclear Sciences, Lower Hutt, New Zealand

Christchurch lies on the layer of Quarternary age fan of gravel deposit. This layer is created when ice age glaciers carving their path along South Island folded mountain and laid their stone loadings onshore. Gravel is considered loose enough so it is not decelerate the seismic wave much. According to USGS' shakeMap, acceleration of seismic wave in Christchurch is 40 % of gravitational acceleration in 0.3 s period wave map. If the acceleration of seismic wave is juxtaposed with Mercalli Modified Intensity scale, the city of Christchurch would have experiencing a horrifying VIII MMI doomsday shake.

SEISMOGRAM DISPLAY OF MC QUEEN VALLEY STATION
note a streak near 12.00 point





Nah, 16 minutes after the primary earthquake, a weaker 5.1 M quake shook Christchurch. Another weaker earthquakes could be seen on seismogram notes before.