11. Triangulation and navigation bases were established along with tide gauges and then topographic and hydrographic surveys were begun. 12. Recent rise in sea levels has been monitored by tide gauges and satellite altimetry ( e . g. 13. One study showed no acceleration in sea level rise in US tide gauge records during the 20th century. 14. A tide gauge in Ocracoke Island reported a tide of 1.5 feet ( 0.45 meter ) above normal. 15. Nevertheless, these observations corroborate the trend of sea level measurements made over the last century using tide gauges . 16. The Fort Denison photographs below show float activated tide gauge instruments in a cabinet and the system's stilling well. 17. Mean sea level was measured at 26 tide gauges : 21 in the United States and 5 in Canada. 18. The PCO has four tide gauges situated around the south west coast, collecting real time tidal and surge data. 19. What was noted on tide gauges around the world are considered to be the effect of the atmospheric pressure wave. 20. This disaster led to the development of the UK National Tide Gauge Network and the UK Storm Tide Forecasting System.
