When do people actually tweet? The data we used to generate the twitter maps New City Landscapes suggests that there are big fluctuations in terms of activity over the course of twenty four hours.
The Tweet-O-Meter by Steven Gray gives extrapolated numbers based on five second intervals as to how many tweets are sent in a specific urban area.
The New City Landscape maps became popular on twitter, third most tweeted topic over the day on tweetmeme on the 30th June, with Steven Fry picking it up and in the media with the Metro and the Daily Mail.
The data for the maps comes in via the Twitter search API where a spatial search is requested, in which the urban area is defined. For the maps however we can only use a fraction of this data set. Only the messages sent from o mobile client that actually includes a lat/long position with the original tweet are of interest. With those ones we have accurat location. There is also some geocoding done by Twitter, based on the profile location, but this is not true location data in a positioning sense.
So if someone makes the simple calculation of tweet numbers based on peak hour tweets per minute, this will not reflect the numbers used for the maps.
The landscapes are generated from a week worth of data. Looking at the temporal dimension of the data, shows the fluctuations in amount of activity there is.
Image by urbanTick / TimeRoses for each city and in comparison.
There are dramatic differences between the hours of the day but also between the days. In London and New York there is a peak on two days. A number of news topics coincide there. Those days are the 28th and the 29th of April 2010. There is the BP oil spill, just a few days old and also the last of the three UK leaders debates taking place on the 29th in the evening.
Image by urbanTick using Wordl / Topics in New York over the period recorded for the New Landscape Maps.
Looking at the # tags used in London the #leadersdebate clearly leads the twitter discussion, where are in New York the #dearsomeone leads. At both places the #nowplaying tag is very active.
Image by urbanTick using Wordl / Topics in London over the period recorded for the New Landscape Maps.