The text 'К западу от Гринвича' and 'К востоку от Гринвича' are present. What do these phrases mean and what geographical reference do they relate to?

The phrases 'К западу от Гринвича' and 'К востоку от Гринвича' translate to 'West of Greenwich' and 'East of Greenwich', respectively. They relate to the Prime Meridian, which passes through Greenwich, London, and serves as the 0° longitude reference point for measuring east-west positions on Earth.