Geography

Although being the second largest eruption in the 20th century, the 1991 eruption is considered one of the smallest in volcano activity.

Death Valley is believed to be the hottest place on Earth in the summer.

The methane gas floats on the water's surface as many tiny bubbles. The density of the resulting gas-water mixture is much less than that of seawater. If a ship finds itself in such an area, due to the lower density, it quickly sinks below the actual sea surface, and the crew is unable even to make an emergency call. The ship sinks.

The Gobi Desert is over 1,680 km (1,045 mi) long in the southwest-northeast direction and over 800 km (500 mi) in the north-south direction.

The Congo Basin shelters all three subspecies of gorilla—the mountain gorilla, the eastern lowland gorilla, and the lowland gorilla.

In the early 19th century, Lower Manhattan was expanded from the natural Hudson shoreline at Greenwich Street to West Street using reclaimed material.

It is the fourth-longest river in North America.

Mount St. Helen is the youngest and the most active volcano of the Cascade Arc.

There are approximately 27,000 abandoned oil and gas wells in the Gulf.

Mount Pinatubo was dormant for approximately 500 years prior to the climatic eruption in 1991.