Theory question 305
Latitude, Longitude and Time(a) Highlight four characteristics each of the following: (i) Time Zone; (ii) International Dateline. (b) If two towns A and B are located on different time zones and the time in town A is 9.00 am while the time in town B is 6.00 pm the same day, calculate the longitude of town B if the longitude of town A is 30° W.
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(a)(i) Time zone: a belt of about 15° of longitude; all places in it use the same standard time; adjacent zones differ by one hour; boundaries follow national or state borders, not exact meridians; there are 24 zones; large countries (USA, Russia) have several.
(ii) International Date Line: follows roughly the 180° meridian; it zigzags to avoid land and island groups; crossing it eastward you go back one day, westward you gain a day; it is in the Pacific Ocean; it marks where each new day begins.
(b) Time difference = 6.00 pm − 9.00 am = 9 hours; 9 × 15° = 135°; B is ahead, so it lies east of A: −30° + 135° = 105°E. Longitude of B = 105°E.
A later time means the town is further east.