MAKE A MEME
View Large Image
| View Original: | Calculating_Magnetic_North.png (1280x1024) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | www.flickr.com | More Like This | ||
| Keywords: text outdoor For a sailor navigating in the dark or fog, a compass can be an essential tool (although GPS has played a major role in relegating compasses to emergency backups.) But compasses don't point north, they point towards "magnetic north" (which is actually a magnetic south pole up in Canada.) It's been slowly drifting towards Russia over the last century, and changes every year. This means compasses change which way they're pointing every year. A nautical chart comes with a compass rose on it, seen here. The top of the chart is true north, and is marked by the star at the top of the compass rose. The inner circle shows the compass readings for the year the chart was published and instructions on how to update it for the current year. Sailors who relied on charts for life-critical navigation needed to keep their charts up to date for many reasons, but keeping the compass constant was one of them. Nowadays this is done electronically. For a sailor navigating in the dark or fog, a compass can be an essential tool (although GPS has played a major role in relegating compasses to emergency backups.) But compasses don't point north, they point towards "magnetic north" (which is actually a magnetic south pole up in Canada.) It's been slowly drifting towards Russia over the last century, and changes every year. This means compasses change which way they're pointing every year. A nautical chart comes with a compass rose on it, seen here. The top of the chart is true north, and is marked by the star at the top of the compass rose. The inner circle shows the compass readings for the year the chart was published and instructions on how to update it for the current year. Sailors who relied on charts for life-critical navigation needed to keep their charts up to date for many reasons, but keeping the compass constant was one of them. Nowadays this is done electronically. | ||||
