Ice Pulse Slides Ice Pulse
Decoding Climate History Through Isotopes
The Deep Freeze
How do we know what the air was like 800,000 years ago?
Annual Accumulation
Every year, snow falls and traps air, dust, and isotopes. It never melts—it just gets compressed into ice.
Climate Time Machine
Glaciers are "archives." The deeper we drill, the further back we travel into Earth's history.
Stratigraphy
Accumulated Layers
Isotope Refresher
Hydrogen-1 (1H)
1 Proton, 0 Neutrons
The "lightweight" version
Evaporates very easily from oceans
Deuterium (2H)
1 Proton, 1 Neutron
The "heavyweight" version
Requires more energy to evaporate
Key Insight: The ratio of Heavy vs. Light water in snow depends on the Temperature at the time of formation.
The Thermometer
δD (Delta D)
The Isotopic Fingerprint
Warm Periods
High energy levels allow more Deuterium to reach the poles.Result: Higher δD values in ice.
Ice Ages
Less energy. Heavy water stays in the ocean; only light water reaches the poles.Result: Lower δD values in ice.
Isotopic Fractionation
COLD WARM
The Greenhouse Link
The Ice Core
Water Isotopes
TEMP
Air Bubbles
Ancient Gas
CO2
When plotted against each other, temperature and greenhouse gases move in lock-step for over 800,000 years.
Vostok Comparison
Synchronized patterns of carbon and climate.
CO2 (ppm)
Deuterium (δD)
420,000 BCE Time Stream Present Day
THE PULSE
1
Heavy isotopes (δD) indicate Warmer Periods
2
Air bubbles provide a direct CO2 archive
3
GHG and Temperature are perfectly synced
LAB: Core Quest
Reconstruct a 10,000-year climate record by analyzing simulated isotopic shifts and impurities in ice cores.
Pulse Points Guided Notes Pulse Points
Guided Notes: Climate History
Scientist:
Date:
01
The Frozen Archive
1. Ice cores serve as proxies: indirect indicators of the past.
2. Glacial layers trap ancient samples of the present during formation.
02
Atomic Variations
Hydrogen-1 (1H)
The "light" version. Evaporates .
Deuterium (2H)
The "heavy" version. Requires energy to evaporate.
03
The Thermometer
Climate Relationship Logic:
Temp
WARM
Energy
D in Ice
HIGH / LOW
δD Value
HIGHER
Scientific Explanation:
Why is heavy Deuterium scarce in Ice Age snow?
04
The GHG Pulse
Bubbles provide direct samples of CO2 and CH4. Unlike isotopes, these aren't proxies—they are the real atmosphere.
Key Correlation:
"In every major climate cycle over the last 800,000 years, greenhouse gas levels and global temperatures move ."
Core Diagram
Deep Freeze Data Worksheet Deep Freeze Data
Vostok Station Analysis Lab
Station
Vostok Core 3G
Archive Scope
420,000 Years
Calibration Formula
Scientists use the δD (Deuterium) ratio to calculate Temperature Change (ΔT) relative to modern times:
ΔT ≈
δD + 440 6
1
Vostok Synchronization Plot
CO2 ppm
δD Ratio
400k BCE 200k BCE Present
A. Correlation Analysis
Does the timing of CO2 peaks align with Deuterium peaks? What does this suggest about the relationship?
B. Isotope Calculation
At 120,000 years ago, δD = -485‰. Calculate the ΔT for this era.
Work Space
C. Causal Complexity
Why are isotopes considered a "proxy" while air bubbles are "direct" samples? Use evidence from the text.
The Physics of Frost
How does fractionation explain why snow becomes "lighter" (more negative δD) during cold glacial periods?
Frozen Fluctuations Visuals Frozen Fluctuations
Visual Glossary & System Map
Isotope
Versions of an atom with the same protons but different neutrons, affecting its mass.
Proxy
An indirect measurement. Since we can't visit 400,000 BCE, we use isotopes as a biological or chemical stand-in.
Deuterium
Hydrogen with a neutron (2H). It is "heavy," requiring more heat energy to evaporate into the air.
Isotopic Fractionation Flow
Ocean Source
H2O & D2O
Energy Check
Cold
Hot
"Higher temperatures provide the kinetic energy needed for heavy Deuterium to escape the ocean's surface."
The Poles
δD Ratio = Temp Marker
Direct Sample
Air bubbles are not proxies. They contain real molecules of ancient CO2, preserving the literal chemistry of the past.
The Delta (δ) Scale
Isotopes are measured as a ratio against a standard. A value of -500‰ indicates the ice is "lighter" than the modern ocean.
Core Quest Lab Guide Core Quest
Simulated Ice Core Drilling Lab
Station #
Mission Objective
Conduct a vertical excavation of a simulated ice core. You will identify key historical markers like volcanic ash, dust layers, and bubble clusters to reconstruct a climate timeline spanning several simulated millennia.
Safety Protocol
No sampling of core material.
Clear workstation of debris.
01 Drilling & Extraction
Phase A: Penetration
Position the drill straw vertically. Push firmly through all frozen layers until base contact is felt. Use a half-turn twist to seal the core.
Phase B: Recovery
Seal the top of the straw with your thumb before extracting. Maintain the vertical orientation of the core at all times.
Phase C: Analysis
Place the core on the stratigraphic ruler. Map each layer from the Top (Modern) down to the Bottom (Ancient).
02
Stratigraphic Observation Log
Depth (mm) Visual Markers Isotope δD (Mock) Climate Inference
Q1: Temporal Scale
If each millimeter of ice represents 5 years, how many years of climate history did your sample capture? Show your work.
Q2: Proxy Interpretation
You encounter a layer with a very low δD value (-520‰) but significant dust. What does this suggest about the climate at that time?
