Explanation:

• Recently, Melting permafrost may have resulted in the leak of approximately 20,000 tonne diesel over 350 square metres of the 60-kilometre-long Ambarnaya river in Russia’s Norilsk — known as the country’s nickel capital. Ground that remains frozen for two or more consecutive years is considered permafrost, according to Colombia University in New York, United States.
• Permafrost is composed of rock, soil, sediments and varying amounts of ice that bind elements together, according to the university. Some permafrost is frozen for tens, hundreds or even thousands of years. Norilsk is constructed on permafrost and there is a threat to its existence because of melting ice due to climate change. Hence both statements are correct.