1. What was the intensity of the Louisbourg Storm?
The Louisbourg Storm, which struck Cape Breton Island, Nova Scotia, Canada on September 25, 1757, was a major hurricane with Category 3+ intensity on the Saffir-Simpson Hurricane Wind Scale. This intensity is more significant than any landfalling storm in Canadian waters since modern records began in 1851. The storm occurred during the colder climate of the 'Little Ice Age' (LIA; c1300-1850), making it an unusual occurrence. The storm's intensity was determined by analyzing historical weather data from ship logbooks and Admiralty records, which provided insights into the storm's characteristics. Comparing the storm's metrics to modern systems helped confirm its classification as a major hurricane. This study contributes to the understanding of unusually severe storms during the LIA and sets the stage for further research on LIA hurricane climatology.
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2. What were the major hurricanes during the Little Ice Age (LIA) and their impacts?
The Little Ice Age (LIA) saw major hurricanes such as the 'Independence Hurricane' that struck New England on August 29, 1775, and the 'Newfoundland Hurricane' of September 9, 1775, which left 4000 dead and became Canada's deadliest hurricane. The LIA's major storms were attributed to cold-enhanced lower tropospheric baroclinicity modifying prevailing westerlies. Historical records show a sharp increase in the number and percentage of historical Atlantic tropical cyclones striking eastern Canada since 1850, correlating to rising sea surface temperatures. The Labrador Current, which originates in the Davis Strait of the Canadian Arctic, plays a critical role in hurricane extratropical transition. The LIA's storminess was also linked to more frequent easterly gales in the English Channel and Approaches during the coldest part of the LIA, the Maunder Minimum (MM; 1645-1715).
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3. What were the specifications of the masts used in the Louisbourg Storm and how were they reinforced?
Masts were constructed from single fir and pine trees and selectively harvested in North America, Great Britain, and the Baltic. They were reinforced to transfer wind energy from the sails to the hull. Invincible's masts were secured by 16 x 5 cm (2') hemp shrouds per side, each tensioned with paired deadeye blocks, the lower block in an iron band bolted to the ship's frame. The diameter topgallant mast was used in the Louisbourg Storm.
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4. What is the historical high tide rise since 1757 at Fortress Louisbourg?
The historical high tide rise since 1757 at Fortress Louisbourg is 0.90 meters (3 feet). This information was revealed through a Parks Canada coastal erosion study at the Fortress Louisbourg National Historic Site, where iron mooring rings set in the remains of a seawall were discovered. The modern high tide was compared to these rings to establish the historical high tide rise. This data is crucial for understanding the impact of sea level rise and flooding on the area.
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