Class Notes (810,849)
Canada (494,298)

coastal ecosystems.docx

11 Pages
Unlock Document

McMaster University
Life Sciences
Luc Bernier

March 4 , 2013 Life Sci 2H03: Environmental Life Sciences Coastal Ecosystems Coastal Ecosystems - balance between tectonic activity and the rate at which the sea floor plates are spreading and changes in ice volumes and temperatures as water expands with warmer temperatures - change of about 120m between glaciation and deglaciation peaks in the sea- level Pattern of Sea Level Changes - relative sea level changes varies regionally - bedrock is rising as ice sheet retreat - rocks are behaving elastically and rebounding in these areas - areas in the ocean where bedrock is sinking due to the added weight of water - balance between the different movements Rebound and Impact on Sea Level - with the mass od ice leads bedrock to sink and flow out due to it’s elastic properties - if all the ice melted, the bedrock rebounds, flows back in and there is a global sea level rise - locally there is an observed sea level drop due to the magnitude of the rebound being greater than the true global sea level rise - what happens at the margin of the ice sheets? Bedrock Sinking and Sea Level Rising in Some Regions - today with the weight disappearing the bedrock is flowing back and the forebuldge is collapsing - there’s sea level rise and our viewpoint is sinking: when we have these two components we see that the observed sea level rise is greater than what is truly happening Ocean Bedrock Sinking and Sea Level Rising - impact of ice weight on the sea level floor - with all the water being in glaciers the ocean crus rises - as sea level rises, with the added weight of water the ocean bedrock is sinking and sea level rises due to the added water - masking the true extent of the sea level rise - far away from the ice sheets is where we observe these phenomenon Rise in Sea Levels in the 20 Century - melting of ice from mountain glaciers and ice sheets - sea level has risen by: 17cm in the last 100 years - melting of mountain glaciers contribute to 5cm of this rise - ice sheets contribute 2cm - the major component is the warming of the sea water: 4cm Bangladesh & Sea-Level Rise - areas in dark green are the most densely populated - +1m: 15 million people affected, 17,000km submerged - +1.5m: 18 million people affected, 22,000km of land submerged - loss of productive land - likely to happen in the next 200 years Impacts of Sea-Level Rise on the Nile River Delta - .5m sea level rise: 3,800000 affected population; 1,800km affected cropland - +1m the delta is truly inundated, 6,100,00 affected populations; 4,500km 2 affected cropland Coastal Inundation of the U.S. with a 1-m Sea-Level Rise - florida - new orleans Sea-Level Rise and Cities - will affect major urban areas on the coast line - 10% of the word’s population in low-lying coastal regions - the trend is increasing - within 10m elevation of sea level: extreme scenario involving the melting of the Antarctic ice sheet - 634 million people: Mumbai, London, New York - 200km in New York that is exposed to sea-level rise of 3m - brown: most densely populated areas - green: buffer zone Coastal Salt Marshes - ecosystems with coastal wetlands that develop in the coastal zones - coast line of the Atlantic and the Eastern Sea board of the un
More Less

Related notes for LIFESCI 2H03

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.