TweeSpeed offers three views of the number of Twitter messages per unit of time. There is the gauge at the front page. There is also a view of the speed by minute for the last day. And finally there is a view of the speed by hour for the last week.
The events around the death of Michael Jackson had a strong impact on Twitter, as already reported by the traditional media such, e.g. CNN.
Looking at the graphs made available by TweeSpeed, I discovered that it was possible to show more history that just the last day or the last week. The graph below starts at June 13, 2009. The rumors and the formal announcement of the death of Michael Jackson caused a sharp increase in the number of Twitter messages on June 25, 2009. The next peak was on June 29, 2009 - when all kind of rumors concerning the cause of death and the funeral arrangements were spreading around. The funeral and memorial service on July 7, 2009 triggered the third peak.
The graph shows also a cyclical trend. The volume of Twitter messages in the past four weeks is significantly lower on Saturdays and Sundays. The peaks occur typically around 20:00 UTC (Coordinated Universal Time), which is around 16:00 US Eastern time and also 13:00 US Pacific Time. The volumes of Twitter messages are at their lowest level between 11:00 and 12:00 UTC, which is around 7:00 and 8:00 US Eastern time and also 4:00 and 5:00 US Pacific Time, when the majority of the population in the United States is probably still sleeping. It looks like Twitter users from the United States are still dominating Twitter usage. Coincidentally, the volumes of Twitter message are at their highest levels during the working hours. Does this mean that Twitter users (especially in the United States) are still allowed to Twitter during working hours ?