The environmental conditions of the Louisiana coast were different in 1812; the sea level was lower, elevation of the city was higher and the expanse of the wetlands far greater. These conditions would have reduced the storm surge by at least several feet, says Mock.
Some of the most valuable sources to Mock’s research were maritime records, which include ship logbooks and ship protests, records submitted by ship captains to notaries detailing damage sustained to goods as a result of weather. Ship logs, kept hour by hour, include data about wind scale, wind direction and barometric pressure.
Because of the war, England bolstered its naval presence, providing Mock, the first academic researcher to conduct historical maritime climate research, with a bounty of records to help him recreate the storm’s path and intensity.
“The British Royal Navy enforced a blockade of American ports during the War of 1812,” said Mock. “The logbooks for ships located in the Gulf of Mexico and the Caribbean Sea had all sorts of valuable information.”
In addition to 12 British Navy logbooks, he was able to use information from logbooks of the USS Enterprise and another from an American merchant vessel. Ship protest records from the New Orleans Notarial Archives provided Mock with some surprising contributions.
“I was initially pretty pessimistic on what I would find in the ship protests,” said Mock. “I thought I’d find a few scraps and be in and out in two days. I was wrong. I found a trove of material and ended up going back eight times.”
Archivists presented Mock with upwards of 100 books for every year, each 800 pages in length and none indexed with the word hurricane. After scouring the records, Mock uncovered nearly 50 useful items related to the 1812 hurricane, including accounts from the schooner, Rebecca, which described the storm in the middle of the Gulf of Mexico in a protest that was filed with notary Marc Lafitte.