Tigris and Euphrates

Tigris

NASA satellite image of downtown Bagdad. The city was founded on the banks of the river thousands of years ago.

The Tigris is approximately 1,180 miles long, rising in the Taurus Mountains of eastern Turkey and flowing in a generally southeasterly direction until it joins the Euphrates near in southern Iraq. The two rivers together form the Shatt al-Arab waterway, which empties into the Persian Gulf. The Tigris is joined by many tributaries, including the Diyala and both the Upper and Lower Zab rivers.

The Tigris is heavily dammed in Iraq and Turkey, to provide water for irrigating the arid and semi-desert regions bordering the river valley. Damming has also been important for averting floods in Iraq, to which the Tigris has historically been notoriously prone following snowmelt in the Turkish mountains around April. Recent Turkish damming of the river has been the subject of some controversy, both for its environmental effects within Turkey and its potential to reduce the flow of water downstream.

Euphrates

A false color-composite satellite image of Euphrates between Lake Asad and the town of Ar-Raqqah in Syria.

The river is approximately 1,730 miles long. It is formed by the union of two branches, the Kara, which rises in the Armenian highlands of today's eastern Turkey north of Erzurum and the Murat, which issues from an area southwest of Mount Ararat, north of Lake Van. The upper reaches of the Euphrates flow through steep canyons and gorges, southeast across Syria, and through Iraq.

The Euphrates provided the water that led to the first flowering of civilization in Sumer, dating from about the 4th millennium BC. Many important ancient cities were located on or near the riverside, including Mari, Sippar, Ur and Eridu. The river valley formed the heartlands of the later empires of Babylonia and Assyria. For several centuries, the river formed the eastern limit of effective Egyptian and Roman control and western regions of the Persian Empire.

Caspian SeaThe Caspian Sea is the largest lake

on Earth by area. It has a surface area of 143,244 square miles and a volume of 18,761 cubic miles. It lies between the southern areas of the Russian Federation and northern Iran. It has a maximum depth of about 3,363 ft. It is called a sea because when the Romans first arrived there, they tasted the water and found it to be salty.

The Volga River (about 80% of the inflow) and the Ural River discharge into the Caspian Sea, but it is endorheic, meaning there is no natural outflow. Thus the Caspian ecosystem is a closed basin, with its own sea level history that is independent of the sea level of the world's oceans. The Caspian became landlocked about 5.5 million years ago. The level of the Caspian has fallen and risen, often rapidly, many times over the centuries. Some Russian historians claim that a medieval rising of the Caspian caused the coastal towns of Khazaria to flood. In 2004, the water level was 92 feet below sea level.

Caspian Wildlife

Caspian White Fish

Caspian Tern

Caspian Seal Caspian Salmon

Bay of Bengal

Bay of Bengal

The Bay of Bengal is a bay that forms the northeastern part of the Indian Ocean. It resembles a triangle in shape, and is bordered on the east by Malay Peninsula, and on the west by India. On the northern tip of the "bay" lies the Bengal region, comprising the Indian state of West Bengal and the country of Bangladesh, thus the name. The southern extremes reach the island country of Sri Lanka, and the Indian Union Territory of Andaman and Nicobar Islands.

Phytoplankton Concentrations in the Sea of Bengal. This is used to monitor cholera outbreaks in the region.

Bay of Bengal- Marine Biology

The Mangrove forests along the Bay of Bengal provide protection from storm surge and erosion. They also provide a protective habitat for many species’ young.

Bay of Bengal is home to a large coral reef system. As a result of the tsunami that struck the region in December of 2004, many of the reefs were partially destroyed.

Marine Animals

The Olive Ridley (Lepidochelys olivacea) is one of the smallest species of sea turtle

Wrasse are commonly found patrolling the reefs in the Bay of Bengal

Although sometimes called the Irrawaddy River Dolphin, it is not a true river dolphin but an oceanic dolphin that lives near coasts and enters rivers

Glory of Bengal Cone often wash up on the beaches in the Bay of Bengal.