Exam preparation:

A 200-km-long shelf has an average depth of 40 m. Roughly how long will it take for the crest of a tidal wave to travel from the open boundary on the left to closed, coastal boundary on the right left? Describe what happens when the wave reaches the closed boundary.

Then draw two diagrams of possible resonance modes (using the lower images as a template for each one). Annotate the nodes and antinodes. Describe or draw the strength of the horizontal currents across the shelf for one of the two diagrams.


A river discharges freshwater into the ocean on the west coast of New-Zealand’s North Island. Draw a cross section of the coastal ocean for this situation. Highlight any gradients in salinity water levels that might occur here due to the freshwater input. Also show the currents that might develop and make clear in which direction they flow. Provide detailed explanation of your diagram.

If we were instead looking at river discharging freshwater on New-Zealands east coast, how would the currents be different compared to the above example.


Descibe aspects of New Zealand’s Oceanography by adressing the following:

  1. Name and describe two major currents systems in the vicinity of New Zealand.

  2. Name and describe the two majorfronts in the vicinity of New Zealand

  3. Name and describe a major seafloor feature in the vicinity of New Zealand

  4. Describe the general pattern of tides around New Zealand

  5. What is a typical rate of sea level rise around New Zealand? and how does this compare to rates of uplift or subsidence of land?

  6. Why do strong flows exist in Cook Strait, and what is a typical current speed here?


In coastal oceanography, we often change from working in the time domain to working in thefrequency domain.

Explain the basics of frequency domain analysis. What do spectra tell us and what are the advantages of working with them?

Then, sketch a possible time series of sea surface height given the power spectrum below. That is, copy the lower graph over to your answer booklet and add the appropriate waves.

Finally, describe a key difference between the wave spectrum below and a model wave spectrum such as a JONSWAP spectrum or a Pierson–Moskowitz spectrum.


In the hypothetical estuary below, a narrow inlet separates the open ocean from the estuary. The inlet has a rectangular cross-section that is 100 m wide, 5 m deep, and 200 m long. The estuary is 2 km × 2.5 km horizontally. This is like Maketū Estuary but with altered dimensions. The water level in the estuary is 1 m higher at high tide than at low tide. Ignoring any river flow, calculate the maximum current speed that occurs in the inlet during ebb tide, explaining all calculations and any assumptions that you make along the way.