More on Felt Reports

In the previous post I mentioned the esoteric art of felt reports and tried to define what they were and how they were used.  In this post I will give an example of  New Madrid felt report and what can be learned from it.

Here is a brief example

New Madrid item 18121228_nmad_2_27

Our correspondent at Cape Girardeau has [unreadable] us with the following notice on the Earthquake.

Dec. [unreadable], 1811.

The concussions of the Earthquake which commenced at two o'clock on Monday morning still continue. We have experienced five severe shocks which split brick houses and damaged five brick chimneys in this place."

J.M.F.

The first thing you will notice is that the account in the original image is very hard to read.  It the reason the Compendium has transcripts of the felt reports to make them easy to read .Next you will notice that the account notes  the time that the first earthquake occurred on December 16, 1811.  Time in 1812 was not standard and so there is a variance in the stated times when earthquakes occurred.  Local time at each location can vary by 30 minutes or more depending on location.  Time was set at each location probably by noting when the sun reached noon then setting a clock accordingly.  The account goes on to note that there were five severe shocks but does not say if they were aftershocks or during the original earthquake on December 16.  And finally the account notes that the damage as being houses split and damage to chimneys.  This damage can be quantified  using a measurement called the Mercali Scale.  This scale will be the subject of another post.