Earthquakes seemed to outline a special feature of earth's crust. Earthquakes let scientists know where the crust was moving. This led to the discovery that the Earths crust was broken up into regions, or plates. Earthquakes happen most often along these plate boundaries. This was evidence that continents can move. The movements of the plates are called plate tectonics. The Earths crust is divided into plates. There are about a dozen large plates and several small ones. Each plate is named for the continent or ocean basin it contains. Scientists know he plates are in motion. They now know the direction and speed of this motion . Plates dont move very fast. They move only a few centimeters a year. This is about the same rate fingernails grow. So you might wonder, what could cause this motion? What supplies the energy to cause this change?

What moves at the same rate that fingernails grow?

Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. Inhaling, or breathing in, occurs when the diaphragm muscle tightens. This increases the size of the chest. This too decreases air pressure inside the lungs. This action allows air and gases to enter the lungs. Exhaling, or breathing out, occurs when the diaphragm muscle relaxes. This decreases the size of the chest. This increases air pressure inside the lungs. This action allows for air to leave the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened. Next, air passes through a passageway that is connected to the windpipe. The air then finds its way to the lungs. In the chest, the windpipe splits so that air enters both the right and left lung.

What happens to the air pressure inside the lungs when the diaphragm muscle tightens?

Crusaders, Mamelukes, and Turks: The Crusaders established a feudal Christian state with Godfrey at its head. They built many impressive churches during the term of the first Latin Kingdom of Jerusalem, but in 1187 they were driven out by Muslim forces under the great warrior Saladin. During the Sixth Crusade (1228 1229), the Holy Roman Emperor Frederick II managed to secure Jerusalem for the Christians by negotiation. The Christians, however, could not hold the city. After they lost Jerusalem, a Mongol invasion swept through, and in 1244 the Mameluke dynasty of Egypt took control, ruling Jerusalem for the next 250 years. The city struggled to rebuild from Crusader wars and invasions. Much of the best Islamic architecture in the city was constructed in the Mameluke era, but the past thousand years had taken their toll: Jerusalem was unable to regain the prosperity it had enjoyed in earlier times. In the early 16th century, the Ottoman Turkish Empire was advancing through the Middle East. Jerusalem fell to the Ottomans in 1517, remaining under their control for 400 years. Suleiman the Magnificent rebuilt the walls and gates in the form they retain to this day. Fountains, inns, religious schools, and barracks were constructed. But when Suleiman died, his empire, including Jerusalem, began a long period of decline. The Holy City remained a backwater until the 19th century, when renewed interest among Christian pilgrims made it the destination of thousands of travelers each year.
What happened to Jerusalem after the Christians lost it?