Question

Ocean sediment cores provide a climate record for the past ________ years.

Answer 1

Ocean sediment cores provide a climate record for the past 70 million years. Ocean sediment cores from the bottom of the ocean work as an event timeline. Every year the ocean sediment was piled above the sediment from the previous year. The deeper the ocean sediment, the older it was.

Answer 2

Ocean sediment core provides a climate record of the past 70 million years.

1880 is the reliable global record which we can say the climate began. Proxies(climate) helps the scientists to determine the climatic patterns even before starting record-keeping.

Some examples of proxies are sub-fossil pollen, lake and ocean sediments, tree rings, and ice cores. Climatic of the time influenced the growth rate of proxies material. It is from proxies where we can recover quantities of particular isotopes from climatic changes.

The combination of proxies can produce temperature reconstruction which is longer the instrumental temperature.