sea-level rise results in less bottom friction and therefore less energy dissipation. This causes the amphidromic points to move further away from the coastal boundaries and more towards the centre its channel/basin. In the M2 tidal constituent Based on Figure 1, there are the following clockwise and anticlockwise amphidromic points: Clockwise amphidromic points north of the Seychelles near Enderby Land off Perth east of New Guinea south of Easter Island west of the Galapagos Islands north of Queen Maud Land Counterclockwise amphidromic points near Sri Lanka north of New Guinea at Tahiti between Mexico and Hawaii near the Leeward Islands east of Newfoundland midway between Rio de Janeiro and Angola east of Iceland The islands of Madagascar and New Zealand are amphidromic points in the sense that the tide goes around them in about 12 and a half hours, but the amplitude of the tides on their coasts is in some places large. See also Kelvin wave Tides Theory of tides References and notes Wave mechanics Tides