Geology Cafe

Oceanography 101

What do you observe on a beach field trip?


Are there any hazard warning posted?
Do you see evidence of pollution?
Is the beach clean of garbage/trash? Are there trash cans present?

Describe weather conditions (sun, humidity, clouds [types], wind direction/intensity).

What level is the tide? (low/med/high, rising/falling).
When is high or low tide relative to the time you spent on the beach?

How wide is the wet sand relative to the wet sand section of the beach?
Are waves reaching the base of seacliff or man-made structures?

Do you see evidence of rip currents? Rip tides?
Can you see evidence of longshore currents (and longshore drift), how fast is it moving?

What direction are the dominant waves arriving from?
How are the waves breaking on the beach? (Directly, or at an angle? Complex or simple?)
Are the waves, spilling, surging, refracting, reflecting? Are wave coming from multiple directions?

What is the average wave period? (Time 10 wave breaks, divide by 10 – compare nearshore and farther out).
What are the wave heights? Where are the surfers clustering?

Identify and estimate numbers of all the birds and other wildlife you observe during your visit.

Can you see kelp beds from the beach? Where are kelp bed relative to where the waves are breaking?
Are there any kelp beds near the mouth of a stream or lagoon?
Are there piles of seaweed on the beach? What kind?

Are there any rocks in the water or tide pools? What animals and sea plants occur on or around them?

Identify shells on the beach.

How high are the sea cliffs (if any)?
Do you see any overhanging cliffs or sea caves?
Are there man-made structures present to prevent coastal erosion?
Are they effective? Do you see evidence of failure?
Do you see evidence of recent rock falls or cliff failures?
If so, how far from the cliff wall does the fallen material extend?

Do you see any fossils in the rocks? Identify them.
Do you see evidence of bioturbation, burrows, root traces, or foot prints exposed in the exposed rock?

Are there “concretions” or other “sedimentary structures” preserved in the rock?
(examples: lamination or massive beds, cross bedding, filled-channel deposits, “red beds” etc.)
Can you determine what kind of “environment” the sedimentary rocks represent?

Can you name the rock formations? How old are they?

What is the steepness of the slopes/cliffs of each of the different rock units?

Do you see evidence of unconformities? Faults? Slumps?

Are any mountains or islands visible in the distance? Can you name them?
Can you see any marine terraces? How many?

Do you see gravel on the beach? Do you see where it is coming from?
Can you see ripple marks in the sand? Where?
Can you see “black” (magnetite) sand? Where is it most abundant?

Do you see any runnels or bars?
What is the slope of the beach?

Is there dry sand along the base of the sea cliff?
Do you see any “wracklines?”

How does the mouth of a stream or lagoon connect with the beach?
What happens to the waves as they enter a stream or lagoon?
Is there active erosion along the channel margins?

How does erosion and deposition processes change at the mouth of the stream/lagoon?

Estimate how a 4-meter tsunami or storm surge might impact “this location” if it occured at high tide.

What kind of plants do you see above the back beach?
What kind plants do you observe within the tidal zone?
What are the characteristics of local plants along creekbeds and hillsides above the coastal tidal zone?

What else did you observe worth noting?