|   |   | Terrain (2003) | Terrain (2005) | 
				  | 
				Arctic Ocean | 
				central surface covered by a perennial drifting polar icepack that averages about 3 meters in thickness, although pressure ridges may be three times that size; clockwise drift pattern in the Beaufort Gyral Stream, but nearly straight-line movement from the New Siberian Islands (Russia) to Denmark Strait (between Greenland and Iceland); the icepack is surrounded by open seas during the summer, but more than doubles in size during the winter and extends to the encircling landmasses; the ocean floor is about 50% continental shelf (highest percentage of any ocean) with the remainder a central basin interrupted by three submarine ridges (Alpha Cordillera, Nansen Cordillera, and Lomonosov Ridge) | 
				central surface covered by a perennial drifting polar icepack that, on average, is about 3 meters thick, although pressure ridges may be three times that thickness; clockwise drift pattern in the Beaufort Gyral Stream, but nearly straight-line movement from the New Siberian Islands (Russia) to Denmark Strait (between Greenland and Iceland); the icepack is surrounded by open seas during the summer, but more than doubles in size during the winter and extends to the encircling landmasses; the ocean floor is about 50% continental shelf (highest percentage of any ocean) with the remainder a central basin interrupted by three submarine ridges (Alpha Cordillera, Nansen Cordillera, and Lomonosov Ridge) | 
				
				  | 
				European Union | 
				- | 
				fairly flat along the Baltic and Atlantic coast; mountainous in the central and southern areas | 
				
				  | 
				Macedonia | 
				- | 
				mountainous territory covered with deep basins and valleys; three large lakes, each divided by a frontier line; country bisected by the Vardar River | 
				
				  | 
				Macedonia, The Former Yugoslav Republic of | 
				mountainous territory covered with deep basins and valleys; three large lakes, each divided by a frontier line; country bisected by the Vardar River | 
				- | 
				
				  | 
				Nepal | 
				Terai or flat river plain of the Ganges in south, central hill region, rugged Himalayas in north | 
				Tarai or flat river plain of the Ganges in south, central hill region, rugged Himalayas in north | 
				
				  | 
				Puerto Rico | 
				mostly mountains, with coastal plain belt in north; mountains precipitous to sea on west coast; sandy beaches along most coastal areas | 
				mostly mountains with coastal plain belt in north; mountains precipitous to sea on west coast; sandy beaches along most coastal areas | 
				
				  | 
				Samoa | 
				narrow coastal plain with volcanic, rocky, rugged mountains in interior | 
				two main islands (Savaii, Upolu) and several smaller islands and uninhabited islets; narrow coastal plain with volcanic, rocky, rugged mountains in interior | 
				
				  | 
				Vanuatu | 
				mostly mountains of volcanic origin; narrow coastal plains | 
				mostly mountainous islands of volcanic origin; narrow coastal plains |