ISOTOPES
An atom with the same number of protons but a different number of neutrons.
Isotopes
Higher δ¹⁸O values indicate
Colder
A deeper ice core layer represents
Older ice deposited further back in time
What period was unusually warm around 1,000 years ago
The Medieval Warm Period
A natural event can cause rapid cooling
Volcanic eruption
Scientists study past climates by referring to...
The Isotopes (ratios in water and ice)
0% > 1% > -8% shows
Which is Older: 10m or 80m?
80m
During 1300-1850 was the period of
The Little Ice Age
What happens to sunlight during a volcanic eruption?
Sunlight is blocked or reduced by ash and aerosols in the atmosphere
Isotope ratio used in ice core is
oxygen-18 (¹⁸O) to oxygen-16 (¹⁶O)
Colder climate shows
Lower δ¹⁸O values
T / F "More Compressed Ice can be found in deeper ice core layers"
True
A large volcanic eruption
is when sudden cooling occurs
T / F (–2‰ → –8‰ is the sharpest drop)
TRUE
Isotopes in snow layers remain preserved for thousands of years because
Snow compacts to form ice, locking in isotope ratios and preventing mixing or alteration.
Volcanic ash cools the atmosphere causing δ¹⁸O values to???
δ¹⁸O values to drop
Estimating the age of each layer involves
counting annual layers, and using known rates of accumulation and isotope changes
δ¹⁸O = –7‰is a climate event when it's...
A cold period, possibly the Little Ice Age or a volcanic cooling event.
δ¹⁸O values drop suddenly after eruptions because
Cooler conditions cause more ¹⁶O to be incorporated into precipitation, lowering δ¹⁸O in ice.
Warming or Cooling Event - The ratio of heavy isotopes (¹⁸O) increases, leading to higher δ¹⁸O values
Warming Event
δ¹⁸O = –10% (global temperature) during the time was
Very cold global temperature
100,000 year old ice core can extract...
direct archive of past atmospheric gasses
Isotope data reveals long‑term warming trends by tracking...
steady increases in δ¹⁸O values through core layers, showing rising temperatures.
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