EESA05 Lecture 10 Notes.docx

3 Pages
Unlock Document

University of Toronto Scarborough
Environmental Science
Caroline Barakat

1 EESA05 Lecture 10  As sea level rises, the equilibrium position of sand bodies offshore moves inland  Barrier islands are strongly affected (they’re like sand bars and forms in front of the coast and in front there’s usually a lagoon)  A small rise in seal level leads to a large migration of the barrier islands  Many of these have been extensively developed, particularly in the southern US  During the last deglaciation, sea levels rose about 130 m and this rise was so rapid that most offshore sand bodies are still moving inland to compensate  Developed barrier islands are a hazard for this reason  Hog Island is migrating inland, leading to the loss of the town of Broadwater  Eustatic – a global sea level, something about expansion of water, coastal erosion  Another way you can get local changes in sea level is by the sinking of continentns, depression of the continents  example of a water ballon bulging on one side (iso-static change, rebound)  Waves increase in sixe with the flowing:  Wind velocity  Length of time that the wind blows (long storms equal long waves)  Fetch: the distance of water over which the wind blows  Waves are characterized by period, wavelength, velocity and amplitude (change in height de to kinetic energy and it’s relation to the height near the shallow zones, near the coast) – (when the waves move, the water isn’t moving, the wave is traveling in the water, towards the cast)  Rogue waves are unexpectedly large waves that arise by the combination of several smaller waves  Thse transient events, but are quite common  Over 20 super-carriers have been lost at sea in the past two decades, some due to waves as high as 25 m rising out of calm seas  Waves: the water of a wave moves in ta circle (prograde)  The wave form itself moves, but the water does not have net forward motion – the motion is the same for a point suspended in the water column  Breaking waves: the ebergy contained within waves is delivered to the shore  As they sow down, their energy is concentrated into a smaller area and the wave gros higher  Once its height is about 1/7 of its length, the wave fron is step emough for the wave to break (to end off at the beach, where surfers catch the wave)  Spiling breakers – gentle break is on a gentle sloped beach  Plunging breakers – on a steeper slope and more violent  Wave refraction : waves refracts around promontories and rocky headlands  Refractions may focus the energy of the waves into a smaller portion of the coast, leading to erosion  In bays, energy is dispersed (as the waves towards the headlands, there is more erosive power and more divergent, so the waves kinda bend and move more violently closer to the edge and the further back the waves go, there is divergence of waves and they turn into straight lines)  Longshore drift: a beach is an ongoing process – sand is continually transported through the beach  The beach will remain only as long as the amount of sand being eoded is balanced by new sand entering the system  Attempts to regulate this flow of sand usually fail 2 EESA05 Lecture 10  The waves are moving the sand and due to sea level rise  Waves approach a beach with a shallow angle, but roll back straight down the gradient  Sand is carried high onto the beach with upwash and carried back down in the backwash  The Toronto islands were created fro the bluff’s sand. As the sand was eroded down to the downtown area, the islands were formed and these islands
More Less

Related notes for EESB18H3

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.