Orbital cycles and ice ages
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Earth's orbit with January and July marked. A classmate says summer comes when Earth is closest to the Sun. Which reply fits NASA, by Esme's reading?
- No; Earth is closest around January 3, in northern winter, and tilt sets seasons
- No; seasons come from the wobble alone
- Correct; the farthest point comes in winter
- Correct; closest means summer everywhere
Read this first
EPICA Dome C temperature record (NOAA NCEI)
Years ago Temperature vs last 1,000 years 20,000 −9.4 °C 128,000 +3.4 °C 140,000 −9.1 °C 410,000 +1.6 °C 800,000 −8.9 °C A student says ice ages come and go over a few centuries. Which reply fits NASA, by Jun's reading?
- Correct; they follow the 11-year sunspot cycle
- No; they come about once in each 10 million years, far apart in time
- No; for 800,000 years they have cycled about every 100,000 years
- Correct; each lasts about 100 years
Earth tilted more and less beside the Sun. A student says a bigger tilt helps ice sheets grow. Which reply fits NASA, by Kira's reading?
- No; ice grows when Earth is farthest from the Sun in northern June
- Correct; tilt has no effect on ice
- Correct; a big tilt means cold summers
- No; larger tilt favors melting, and a smaller tilt lets ice build
A timeline divided into equal cycles. NASA: in about 13,000 years precession will flip which hemisphere has more extreme seasons. What fraction of the 25,771.5-year cycle is that, by Luz's math?
- About half
- About a tenth
- About a quarter
- About twice
EPICA Dome C temperature record (NOAA NCEI)
Years ago Temperature vs last 1,000 years 20,000 −9.4 °C 128,000 +3.4 °C 140,000 −9.1 °C 410,000 +1.6 °C 800,000 −8.9 °C Using the EPICA table, what is the range from the table's coldest value (−9.4 °C) to its warmest (+3.4 °C), by Noah's math?
- About 6 °C
- About 128 °C
- About 3.4 °C, the warmest value
- About 12.8 °C
Four evidence cards, labeled A to D. Which evidence best supports Milankovitch's idea, by Pia's reading (NASA)?
- Ice ages repeating each century
- Sediment and ice cores show climate swings timed with orbital cycles
- Tilt staying fixed for a million years while the ice sheets came and went
- One cold winter after a far aphelion
EPICA Dome C temperature record (NOAA NCEI)
Years ago Temperature vs last 1,000 years 20,000 −9.4 °C 128,000 +3.4 °C 140,000 −9.1 °C 410,000 +1.6 °C 800,000 −8.9 °C Model data: cold periods come every 100,000 years for the last 800,000 years and every 41,000 years before that. Which cycles match each part, by Ren's reading?
- Orbit shape recently; tilt earlier
- Tilt recently; orbit shape earlier
- The 26,000-year wobble for both parts
- The yearly orbit for both parts
Orbit shape, tilt and wobble, each with its cycle. Which summary of Milankovitch cycles fits NASA, by Zee's reading?
- They change the Sun's brightness each year
- Orbit shape (about 100,000 years), tilt (41,000) and wobble (26,000) shift sunlight
- Orbit shape (26,000), tilt (100,000) and wobble (41,000)
- They set the seasons by distance
Which summary of how ice ages are paced fits NASA, by Ari's reading?
- Hotter summers build ice sheets at high latitudes, and the ice warms Earth
- Each ice age lasts about 100 years
- A larger tilt builds the ice
- Cooler high-latitude summers let ice build, and bright ice adds cooling
EPICA Dome C temperature record (NOAA NCEI)
Years ago Temperature vs last 1,000 years 20,000 −9.4 °C 128,000 +3.4 °C 140,000 −9.1 °C 410,000 +1.6 °C 800,000 −8.9 °C Which summary of the EPICA Dome C record fits NOAA, by Bo's reading?
- Glacials warmer than interglacials
- About 800,000 years of Antarctic temperature, with glacials near −9 °C
- About 800 years of steady temperature
- Glacials about 90 °C colder