That's because the two countries have been really close and claiming that there's no "actual" difference between the two countries, and since Russia was in charge of Ukraine's territory,multiple times through history and is smaller, people called it Little Russia. hope it helps.
Answer: EXCESS NUTRIENTS FROM FERTILIZERS
Explanation: Fertilizer is an organic or synthetic chemical materials which contains certain nutrients or chemical compounds required by plants for proper growth and development.
Euthrophication is the process of increase in the plant population in water bodies such as Algae and other higher plant species due to the release of nutrients into water bodies. This nutrients can be washed through the flooding of farm lands,erosion etc. Example of fertilizers include livestock manures,Ammonium nitrogen fertilizer,Nitrate nitrogen fertilizer,Amide nitrogen fertilizer,Agricultural waste etc.
Earthquakes are concentrated along where there is usually large faults of concentration.
Hope this Helps!