Deltas at risk (3rd feb) Syvitski

Question 1

Research showing (accelerated compaction)… has led scientists to propose..(rate of eustatic sea level rise….)

Answer 1

Research showing the accelerated compaction associated with petroleum and groundwater mining can exceed natural subsidence has led scientists to propose that the rate of eustatic sea level rise is often smaller than the rate of isostatic controller subsidence (sinking)

Question 2

Why delta plains are useful..

Answer 2

Delta size relative to river discharge and sediment load. Flat = easy agriculture and organic soils.

Question 3

Cons of living on a Delta..

Answer 3

Engineering gives people more confidence to live in delta areas.
Isostasy (regional earth surface load changes)

Question 4

Syvitski evaluated… (models)

Answer 4

Comparison of subsidence models, sea level rise models and impact of natural / humans. Looked at sediment load before engineering constructions and erosion examples.

Question 5

Syvitski finds (human impact on deltas..)

Answer 5

Human impacts on deltas have changed the rate of subsidence and control on routing and sediment supply is even more common. Delta subsidence accelerated.
Accelerate shoreline erosion - threatens health of mangroves and wetlands and increased salinity of agricultural lands.

Question 6

Scientists will likely turn their attention too..

Answer 6

The impact of large scale engineering projects and how fragile infrastructure will be effected by rare events. No to re-assess assumption hard engineering and altering delta areas is the best way to manage a delta plain area.

Question 7

What was the cause of subsidence.

Answer 7

Accelerated anthropogenic compaction through petroleum extraction or groundwater increases subsidence over natural rates. Sinking of land takes TIME.