Isostatic and eustatic sea level changes Flashcards
What is eustatic sea level change?
A rise or fall in water levels caused by a change in the volume of water, which is a global change and occurs relatively quickly.
What occurs during isostatic sea level change?
Movement of the land relative to the sea, resulting in a local rise or fall of the ground over time.
What causes global sea level increases during the ice age?
Melting ice returns water to the sea, causing sea levels to increase globally.
What is thermal expansion in the context of sea level changes?
An increase in the volume of ocean water caused by global temperature increases.
How did the onset of the ice age affect sea levels?
The temperature fell, leading to water freezing into glaciers and a subsequent fall in sea level.
What is the relationship between isostatic and eustatic changes during the last glacial period?
They are linked but happen at very different rates.
Fill in the blank: Eustatic changes are caused by a change in the _______.
[volume of water]
True or False: Isostatic sea level changes occur quickly and are global in nature.
False
What happens to sea levels when the ice age ends?
Sea levels increase due to the melting ice returning water to the sea.
What are two common reasons for sea-level changes?
- Ongoing isostatic rebound and melting from the last ice age.
- Global warming leading to rising average temperatures.
By how much did average global temperatures rise from 1880 to 2012?
0.85 degrees Celsius
What was the average sea level rise from 1870 to 2010?
21 cm
What causes sea levels to rise due to climate change?
Melting of ice sheets and thermal expansion of seawater.
What tectonic activity affected Aceh province’s coastline?
Tectonic subsidence resulting in a ria.
What happens to coral reefs in tectonically active zones?
They can be raised and subsequently eroded by wave action.
True or False: Tectonic changes to coastlines are common and widespread.
False
Fill in the blank: The planet is getting hotter due to _______.
global warming
What is isostatic rebound?
The process of the Earth’s crust rising after being compressed by ice sheets.
What is a ria?
A coastal inlet formed by the flooding of a river valley.
What are the effects of changing sea levels being felt globally?
Increased flooding, coastal erosion, salinisation, and migration issues
Millions of euros have been invested in protective measures like the Delta works in the Netherlands.
Which region is experiencing more than 20 meters of erosion each year?
Sundarbans region of West Bengal and the low-lying delta of Bangladesh
This area is among the fastest eroding coastlines globally.
What natural disasters are increasing in frequency due to changing sea levels?
Cyclones and associated tidal surges
These events are exacerbated by rising sea levels.
What challenges are low-lying island states in the Pacific Ocean facing due to sea-level rise?
Increased rates of salinisation, coastal erosion, and storm surges
These challenges are forcing many residents to consider migration.
Which part of the UK has a high risk of flooding and destruction?
The east coast
This area is densely populated and contains critical infrastructure.
