This is a contradiction in terms. A place cannot be at both 0 degrees latitude and 40 degrees north latitude. A country could theoretically control land at both latitudes (such as Britain had with the British Empire if mapped ahistorically), but no such country exists today.
Antarctica is located 0 degrees north and 40 degrees east.
Greenland is located at approximately 70 degrees north latitude and 40 degrees west longitude.
Russia.
That point is located roughly 690 miles from the north pole, in north-central Greenland.
This location is within the country of Turkey, specifically just north of the large town of Bozüyük in the province of Bilecik.
Antarctica is located 0 degrees north and 40 degrees east.
At 40 degrees west and 70 degrees north, you would find the country of Iceland.
Turkey.
Spain
Since California is located in USA, the nearest country east of USA and at 40 degrees north latitude is Portugal.
Antarctica is located 0 degrees north and 40 degrees east.
Greenland is located at approximately 70 degrees north latitude and 40 degrees west longitude.
That point is in Turkey.
Russia.
That point is located roughly 690 miles from the north pole, in north-central Greenland.
This location is within the country of Turkey, specifically just north of the large town of Bozüyük in the province of Bilecik.
Turkey is located at 40 degrees north latitude and 40 degrees east longitude. It is located in Europe near the Black Sea.