Earthquake v Encyclopedia

In the early hours of Saturday a 7.1 magnitude earthquake struck just outside of Darfield near Christchurch. You know the story, it has been everywhere for almost a week. On Saturday, if you were not directly affected, you, like me were glued to the media hungry for more information.

New Zealanders surged online for information about the quake. As the day progressed and in the days since, people have been searching out more and more information about earthquakes. GeoNet, a tremendous source of seismic information saw a massive increase in traffic.

Te Ara received more visitors than ever before and our page views doubled:

Te Ara's pageviews over the previous month
So what was everyone looking at? Well…

Active faults
The most viewed page by far was this map of active faults. Visitors would have quickly noticed there aren’t any active faults marked near Darfield. Faults are only considered active if they have moved (and broken the earth’s surface) in the past 120,000 years. Kelvin Berryman, manager of the natural hazards platform at GNS Science explains:

‘Before Saturday, there was nothing in the landscape that would have suggested there was an active fault beneath the Darfield and Rolleston areas … Geologists have no information on when the fault last ruptured as it was unknown until last weekend. All we can say at this stage is that this newly revealed fault has not ruptured since the gravels were deposited about 16,000 years ago.’ (

Due to the interest in the map, I have created a high resolution version and added the epicentre of Saturday’s quake. I’ve also added the 22-km-long surface rupture (fault trace) which represents the previously hidden fault line.


Historic earthquakes
Our Historic earthquakes entry was also popular, perhaps as people tried to put this disaster in context. These were the quakes they were most interested in (in order of page views):

What causes earthquakes?
As well as information on active faults people were clearly interested in what causes earthquakes and seismic activity in New Zealand. We have a number of diagrams that illustrate various aspects of earthquakes that were amongst the most viewed pages:

That last one is very similar to this animation created by Chris McDowall using information from GeoNet. It visualises six months of New Zealand earthquakes and ends several days after the Darfield quake.

Damage, ruptures and distortion
The Deans family were the first permanent European settlers in the Christchurch area. This photo of their homestead was the sixth most viewed page on the site. The registered historic place, built in the late 1800s, was severely damaged in the quake.

I find the pictures of the damage left by Saturdays quake hard to refer to as stunning, a typically positive term, however they did stun me. Visitors to Te Ara were obviously fascinated by ruptures and land distortion, such as these:

Around the world
There was also a lot of interest from around the world with traffic increasing 50% from the United States, 76% from Australia, 89% from the United Kingdom, 111% from Canada and a whopping 500% increase from the Dominican Republic (which, admittedly was only an increase from 1 visitor last week to 6 visitors this week, so far).

We’re pleased that Te Ara’s wide range of information, photos, maps and diagrams about earthquakes was able to help people understand what has been going on in Christchurch over the last few days, but do you have a question that you can’t find an answer to? Let us know in the comments below…

3 comments have been added so far

  1. Comment made by Heath Sadlier || September 10th, 2010

    …and just to hand, GNS Science have posted a video of the fly-over of the fault trace:

  2. Comment made by Caren || September 10th, 2010

    This graphic on the Stuff siteis a good visual representation of the 395 seismic shocks experienced in Canterbury since Saturday morning.

  3. Comment made by Ross Somerville || September 13th, 2010

    My sister in Sydney sent me a link to this nifty visualisation of GeoNet data on the earthquake and its aftershocks – 500 so far, though my geologist niece points out that many of these would not be felt on the surface.

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