Utrecht University
Paleoceanography
Lecture notes
Name: Sanne Maas
Solis-id: 5133017
3rd period
Utrecht University
Bachelor Aardwetenschappen
Name class: Paleoceanography
Teacher: Dr. M. Ziegler
,Contents
Lecture 1 – Introduction & Basics Oceans ............................................................................................... 3
Lecture 2 – Earth’s radiative balance .................................................................................................... 15
Lecture 3 – Stable isotope thermometry .............................................................................................. 22
Lecture 4 – Dynamics ............................................................................................................................ 29
Lecture 5 – Water masses ..................................................................................................................... 40
Q&A lecture ........................................................................................................................................... 49
Guest lecture – Modelling in paleoceanography .................................................................................. 52
Part 2 – Chemical Oceanography .......................................................................................................... 57
Lecture 1 – Organic Matter Production ................................................................................................ 58
Lecture 2 – Organic matter export and degradation ............................................................................ 70
Lecture 3 – Marine calcium carbonate dynamics ................................................................................. 80
Lecture 4 – Carbon pumps, glacial-interglacial change ......................................................................... 94
Lecture 5 – Marine silicon cycle .......................................................................................................... 105
Q&A lecture ......................................................................................................................................... 116
List of key terms .................................................................................................................................. 118
Lecture 1 .......................................................................................................................................... 118
Lecture 2 .......................................................................................................................................... 119
Lecture 3 .......................................................................................................................................... 119
Lecture 4 .......................................................................................................................................... 119
Lecture 5 .......................................................................................................................................... 120
2
,Lecture 1 – Introduction & Basics Oceans
Paleoceanography=
studying past climate change through marine sediment
cores
Color changes show rapid climate change
→ cores are from see in Japan
Second year fieldwork
- Red sediments = deep sea clays end of Cretaceous
- Grey mass = KBG boundary
- Paleoceanography
→ we apply proxies to reconstruct how the ocean behaves, what
happens to the climate during these transitions
Why is it interesting to study these past climates?
- One of major motivation is modern situation that we are
in today
- On average we increase every year the CO2 concentration
– 3-4 ppm
- If we look at the last 60 years you see a steady increase
- Lot of the information is coming from ice cores
→ the further you drill into the ice the older the ice gets
& with this technique we can reconstruct CO2
concentrations in the atmosphere
o Little air bubbles in the ice
o We can measure what the CO2 concentration was in the past
Ice CO2 record
- We are around 450 ppm or so
- Couple of decades ago we were around 280 ppm
o During interglacial periods we quite often got this number
in last million years
o In between interglacial periods (100,000 years’ time cycle)
we dropped to 180-200 ppm
- Values above 500 are by far incomparable with any point in time in
last million years
→ very unusual concentrations
3
, o We have to look further back to find numbers like
this in the past
o We cannot use ice cores for this, the ice is not that
old
CO2 leads to warming of the atmosphere
- Temperature increases
- Pre-industrial period is below 0, so tells us
that the overall amplitude is already 1,25
degrees
- We are getting very close already to the 1,5
degree goal
→ probably much further warming (maybe 3
degrees)
Temperature departure from average 2020 with respect to
1981-2010
- Some regions (eastern part pacific) cooler
- So there is variability, not everything gets warmer
uniform
- But we are definitely going to a warmer planet
Scenario’s
- Depending on the difference emission scenario’s
- Predictions tell us that compared to modern
temperatures we will further warm by
o Most optimistic scenario 0,5 degree at
the end of the century
o Pessimistic scenario up to 4 degrees at
the end of the century
- The paleoclimate records really help us to help
that in a bit of perspective
4
Paleoceanography
Lecture notes
Name: Sanne Maas
Solis-id: 5133017
3rd period
Utrecht University
Bachelor Aardwetenschappen
Name class: Paleoceanography
Teacher: Dr. M. Ziegler
,Contents
Lecture 1 – Introduction & Basics Oceans ............................................................................................... 3
Lecture 2 – Earth’s radiative balance .................................................................................................... 15
Lecture 3 – Stable isotope thermometry .............................................................................................. 22
Lecture 4 – Dynamics ............................................................................................................................ 29
Lecture 5 – Water masses ..................................................................................................................... 40
Q&A lecture ........................................................................................................................................... 49
Guest lecture – Modelling in paleoceanography .................................................................................. 52
Part 2 – Chemical Oceanography .......................................................................................................... 57
Lecture 1 – Organic Matter Production ................................................................................................ 58
Lecture 2 – Organic matter export and degradation ............................................................................ 70
Lecture 3 – Marine calcium carbonate dynamics ................................................................................. 80
Lecture 4 – Carbon pumps, glacial-interglacial change ......................................................................... 94
Lecture 5 – Marine silicon cycle .......................................................................................................... 105
Q&A lecture ......................................................................................................................................... 116
List of key terms .................................................................................................................................. 118
Lecture 1 .......................................................................................................................................... 118
Lecture 2 .......................................................................................................................................... 119
Lecture 3 .......................................................................................................................................... 119
Lecture 4 .......................................................................................................................................... 119
Lecture 5 .......................................................................................................................................... 120
2
,Lecture 1 – Introduction & Basics Oceans
Paleoceanography=
studying past climate change through marine sediment
cores
Color changes show rapid climate change
→ cores are from see in Japan
Second year fieldwork
- Red sediments = deep sea clays end of Cretaceous
- Grey mass = KBG boundary
- Paleoceanography
→ we apply proxies to reconstruct how the ocean behaves, what
happens to the climate during these transitions
Why is it interesting to study these past climates?
- One of major motivation is modern situation that we are
in today
- On average we increase every year the CO2 concentration
– 3-4 ppm
- If we look at the last 60 years you see a steady increase
- Lot of the information is coming from ice cores
→ the further you drill into the ice the older the ice gets
& with this technique we can reconstruct CO2
concentrations in the atmosphere
o Little air bubbles in the ice
o We can measure what the CO2 concentration was in the past
Ice CO2 record
- We are around 450 ppm or so
- Couple of decades ago we were around 280 ppm
o During interglacial periods we quite often got this number
in last million years
o In between interglacial periods (100,000 years’ time cycle)
we dropped to 180-200 ppm
- Values above 500 are by far incomparable with any point in time in
last million years
→ very unusual concentrations
3
, o We have to look further back to find numbers like
this in the past
o We cannot use ice cores for this, the ice is not that
old
CO2 leads to warming of the atmosphere
- Temperature increases
- Pre-industrial period is below 0, so tells us
that the overall amplitude is already 1,25
degrees
- We are getting very close already to the 1,5
degree goal
→ probably much further warming (maybe 3
degrees)
Temperature departure from average 2020 with respect to
1981-2010
- Some regions (eastern part pacific) cooler
- So there is variability, not everything gets warmer
uniform
- But we are definitely going to a warmer planet
Scenario’s
- Depending on the difference emission scenario’s
- Predictions tell us that compared to modern
temperatures we will further warm by
o Most optimistic scenario 0,5 degree at
the end of the century
o Pessimistic scenario up to 4 degrees at
the end of the century
- The paleoclimate records really help us to help
that in a bit of perspective
4
