Chris McDowall

GeoNet web traffic plotted against aftershocks - Seeing Data

Sep 13, 2010

GeoNet have created a line chart to show the volume of web traffic they received in the days following the 2010 Christchurch earthquake. There are three main things to keep in mind when you read the graph: The green line shows the number of hits their website was receiving per second (in one minute averages). The orange diamond represent the timing of significant aftershocks. The number above the orange diamond records the magnitude of the seismic event. It is apparent that spikes in web traffic were correlated with the incidence of seismic events. Also note that the greatest traffic volumes occur during the day on Monday, Tuesday and Wednesday. It would be interesting to know the reason for this. Possible factors include growing public awareness of the GeoNet website and that people are more … Read More

Friday morning video – Asteroid Discovery From 1980 – 2010 - Seeing Data

Sep 10, 2010

An incredible video created by Scott Manley shows the locations of known asteroids starting in 1980. As asteroids are discovered they are added to the map and highlighted white so you can pick out the new ones. Armagh Observatory host a current map of the solar system where you can see a two dimensional projection of known near-Earth objects. Bump up the resolution, dim the lights and full-screen it. (via BoingBoing and @auchmill). Read More

Six months of seismic activity in under a minute - Seeing Data

Sep 08, 2010

I created a video to animate six months of 2010 New Zealand seismic activity data picked up by the GeoNet sensors. The animation begins in April and ends a few days after the 7.1 quake that hit Christchurch on September 4. Keep in mind three things when you view the video. Blue circles represent seismic activity recordings. Each event leaves behind a small, pale red dot to show the overall pattern. Most events are either small, deep or both. Note how sparse the pattern of spots across Canterbury is until early September. [vimeo width=”690″ height=”707″][/vimeo] The data comes from the excellent folks at the New Zealand Geonet project. You can download the data as a spreadsheet from I created the individual animation frames using Python and matplotlib. I stitched the images together with … Read More

Two Christchurch quake animations - Seeing Data

Sep 08, 2010

A quick post to note that Paul Nicholls has created a nice animation of the Christchurch Quake Map. He’s representing several variables at once. In addition to location and time, he depicts both magnitude (circle size) and depth (circle colour) while providing a running textual report of seismic events. It is well worth checking out. I started creating my own animated map on Tuesday morning. You can see my experiment here. I am happy with how the information is presented but unfortunately I do not have the time this week to take it any futher (e.g. adding time controls, refining layout, handle mobile devices). In the interests of pushing the Christchurch quake map site forward, I have shared my code with Paul. A screenshot from my quick earthquake animation experiment. Read More

Hand drawn chart of aftershock intensity - Seeing Data

Sep 06, 2010

Mike Dickison, from the excellent Pictures of Numbers information design blog, has been working with GeoNet’s seismic data. This morning Mike asked the Internet “has anyone produced a graph of all the aftershocks and their intensity over the past two days?” It seemed that nobody had, so he created his own … by hand. The figure below is a scanned copy of Mike’s bar graph of aftershocks following the large quake. Note the tall line at the far left of the chart. That is not the Y axis – that’s the big one. A chart created with actual graph paper is a rare and wonderful thing. This made my day. Read More

Mapping quakes in Canterbury - Seeing Data

Sep 05, 2010

I awoke yesterday morning to a stream of tweets and news articles reporting a massive earthquake near Christchurch. I followed the coverage throughout the day, reading the surreal accounts of everyday scenes turned upside down. Every so often an aftershock would ripple across Twitter and I would get a sense of the rhythm, if not the magnitude, of the event. This morning I decided to try and map the data myself. I downloaded the seismic activity data from the GeoNet data portal. GeoNet is a joint geological hazard monitoring project between GNS and the Earthquake Commission. One of the great things about GeoNet is the fact that their data is freely available for researchers and members of the public to download and analyse. Late this morning I wrote a short programme to parse the GeoNet data and … Read More

Why visualise data? - Seeing Data

Sep 03, 2010

Why visualise data? In the introduction to his classic text, The Visual Display of Quantitative Information, Edward Tufte answers this question in three words. “Graphics reveal data”. To illustrate his point Tufte asks the reader to examine four datasets of eleven (x, y) datapoints, collectively known as Anscombe’s quartet. I’ve reproduced them in the figure below. The datasets that constitute Anscombe’s quartet share identical basic statistical properties and can be described by the same linear model. Take a look at them. What can you see? If you’re anything like me, the answer is probably “not very much”. When the data is graphed their characteristics and differences become immediately apparent. Visualisation renders complex data accessible. Graphics and interactive visualisations make visible things we … Read More