Aclimatologist removes an ice core sample from the antarctic. she finds volcanic ash at the bottom of the core, followed by increasing amounts of dissolved oxygen as she goes to the top of the core sample. which of the following can be concluded based on this information?
after a volcano erupted, all plants in the surrounding area died.
a volcano erupted due to the increasing amount of oxygen in the atmosphere.
as the amount of oxygen in the atmosphere decreased, a volcano erupted.
a volcano erupted, followed by a period of increased oxygen in the atmosphere.

Option (4)

Explanation:

A volcano is usually formed where the magma forces to rise up towards the surface of the earth. it usually takes place due to the convergent or divergent of two moving plates and also in the hotspot region. Various types of toxic gases are produced during the time of volcanic eruption such as carbon dioxide (CO₂), hydrochloric acid (HCl), carbon monoxide (CO), hydrogen sulfide (H₂S), and also some amount of water vapor (H₂O) is released into the atmosphere. In addition to that, pyroclastic materials and volcanic ash and blocks also are erupted from the volcano.

On the other hand, the dissolved oxygen is produced when there is abundant oxygen in the atmosphere, which are produced extensively by the terrestrial and aquatic plants, as they carry out the process of photosynthesis.

Thus, from the above-given information, where climatologists observed the volcanic ash at the bottom of the core and high amount of dissolved oxygen at the top, it can be concluded that initially, a volcano has undergone eruption, after which there was a period of rapidly increasing oxygen in the atmosphere.

Hence, the correct answer is option (4).