Instruct: Given a question, retrieve documents that answer the question.
Query: What is the surface area of the Caspian Sea?
This is a list of terrestrial lakes with a surface area of more than approximately 2,000 square kilometres (800sqmi), ranked by area.[1][2][3] This list does not include reservoirs and lagoons.
The Baltic Sea is the world's largest inland brackish sea. Only two other brackish waters are larger on some measurements: The Black Sea is larger in both surface area and water volume, but most of it is located outside the continental shelf (only a small percentage is inland). The Caspian Sea is larger in water volume, but—despite its name—it is a lake rather than a sea.
The Convention grants jurisdiction over 15 miles of territorial waters to each neighboring country, plus additional 10 miles of exclusive fishing rights on the surface, while the rest is international waters. The seabed, on the other hand, remains undefined, subject to bilateral agreements between countries. Thus, the Caspian Sea is legally neither fully a sea nor a lake.[59]
In the same manner as the Dead Kultuk, the Kaydak Inlet had a distinct coastline in former times, but since the 1990s, with higher Caspian Sea levels, the water penetrates inland through the neck of the bay producing waterlogged marshes. Nowadays both the bay and the inlet are filled with Caspian Sea water. The water in the shallow inlet has striking colours, in which delicate tones of blue or of brown predominate according to the seasons.
The area was cartographed by Fedor Ivanovich Soimonov during the Caspian Expedition, which surveyed the Caspian Sea from 1719 to 1727, but was only accurately described later by G. S. Karelin in 1832.
This peninsula is a vast low-lying depression with salt marshes and salt lakes. Parts of it lie between 20 and 30 m below sea level, lower than the Caspian. The area provides an important habitat for thousands of Goitered Gazelles.
The area was mapped by Fedor Ivanovich Soimonov during the Caspian Expedition, which surveyed the Caspian Sea from 1719 to 1727.
A global sea level rise of roughly would cause the ocean surface to be higher than the highest point of an area between the ocean and the Caspian, forming a narrow channel straddling the lake in the area between the Sea of Azov and the Caspian Sea, potentially placing the Caspian Depression area under water.
The Caspian turtle (Mauremys caspica), although found in neighboring areas, is a wholly freshwater species. The zebra mussel is native to the Caspian and Black Sea basins, but has become an invasive species elsewhere, when introduced. The area has given its name to several species, including the Caspian gull and the Caspian tern. The Caspian seal (Pusa caspica) is the only aquatic mammal and is endemic to the Caspian Sea, being one of very few seal species that live in inland waters, but it is different from the those inhabiting freshwaters due to the hydrological environment of the sea.
Eridania Lake is a theorized ancient lake with a surface area of roughly 1.1 million square kilometers. Its maximum depth is 2,400 meters and its volume is 562,000 km. It was larger than the largest landlocked sea on Earth, the Caspian Sea and contained more water than all the other martian lakes together. The Eridania sea held more than 9 times as much water as all of North America's Great Lakes. The upper surface of the lake was assumed to be at the elevation of valley networks that surround the lake; they all end at the same elevation, suggesting that they emptied into a lake.
The Caspian Sea is the largest lake on Earth by both area and volume, with a surface area of 371,000 square kilometres (143,244 mi²) and a volume of 78,200 cubic kilometres (18,761 mi³). It is a landlocked endorheic body of water and lies between Asia and Europe. It has a maximum depth of about . It is called a sea because when the Romans discovered it they tasted the water and found it to be salty. It has a salinity of approximately 1.2 percent, about a third the salinity of sea water.
Talesh is located on the southwestern coast of the Caspian Sea. Talesh County, covering an area of 2373 square kilometers, is ¼ of surface area of Gilan Province.
The lake is a remnant of the Paratethys sea, which started to dry from the Pleistocene epoch, leaving Lake Urmia and the Caspian Sea and other bodies of water. The lake has a surface area of about , but most of this is dry. Water only covers . The lake only reaches a depth between to . The most important water supply is the river Qom.
The ecoregion is approximately contained within the Caspian Depression, and sunken geological region feeding in to the Caspian, the surface of which is itself at below worldwide sea level. The northern section is almost 900 km wide, and stretches up to 300 km inland across Russia and Kazakhstan. The sector along the southeast coast of the Caspian is mostly in Turkmenistan. Elevations throughout the ecoregion range between -28 and +100 meters. The dry areas were once underwater, but as the sea has slowly receded the dry areas have revealed a landscape of sand dunes, ridges, salt domes, salt pans ('shors'), and clay deserts ('takyrs'). 
The climate of the ecoregion is represented by that in the Volga delta, in the Astrakhan Nature Reserve, where the climate is cool semi-arid (Köppen climate classification BSk). This climate is characterized by high variation in temperature, both daily and seasonally; with low precipitation. Average annual precipitation in the Caspian lowlands is 198 mm. Average temperature in January is , and in July is 
The wide and endorheic Caspian Sea has a north–south orientation and its main freshwater inflow, the Volga River, enters at the shallow north end. Two deep basins occupy its central and southern areas. These facts lead to horizontal differences in temperature, salinity, and ecology. The Caspian Sea spreads out over nearly 750 miles (1,200 km) from north to south, with an average width of 200 miles (320 km). It covers a region of around 149,200 square miles (386,400 square km)—bigger than the region of Japan—and its surface is about 90 feet (27 meters) below sea level. The sea bed in the southern part reaches as low as 1,023 m (3,356 ft) below sea level, which is the second lowest natural depression on earth after Lake Baikal (−1,180 m, −3,871 ft). The ancient inhabitants of its coast perceived the Caspian Sea as an ocean, probably because of its saltiness and large size.
Steppe: Since the Don and Volga are not significant barriers the history of most of this area is part of the general history of the Pontic-Caspian steppe. Since this area is far from the centers of literate civilization it is hard to know the details of what happened. Variations in dates below represent early ancestors, late survivals and other irregularities. 
The main water sources are surface waters. However, only 24 of the 8,350 rivers are greater than in length. All the rivers drain into the Caspian Sea in the east of the country. The largest lake is Sarysu (67 km²), and the longest river is Kur (1,515 km), which is transboundary with Armenia. Azerbaijan's four main islands in the Caspian Sea have a combined area of over thirty square kilometers.
A theory proposed by Andrey Tchepalyga of the Russian Academy of Sciences dates the flooding of the Black Sea basin to an earlier time and from a different cause. According to Tchepalyga, global warming beginning from about 16,000 BP caused the melting of the Scandinavia Ice Sheet, resulting in massive river discharge that flowed into the Caspian Sea, raising it to as much as above normal present-day levels. The Sea of Azov rose so high that it overflowed into the Caspian Sea. The rise was extremely rapid and the Caspian basin could not contain all the floodwater, which flowed from the northwest coastline of the Caspian Sea, through the Kuma-Manych Depression and Kerch Strait into the Black Sea basin. By the end of the Pleistocene this would have raised the level of the Black Sea by some below its present-day level, and flooding large areas that were formerly available for settlement or hunting. Tchepalyga suggests this may have formed the basis for legends of the great Deluge.
The Garabogazköl Aylagy or Kara-Bogaz-Gol (, black (or mighty) strait lake) is a shallow inundated depression in the northwestern corner of Turkmenistan. It forms a lagoon of the Caspian Sea with a surface area of about . It is separated from the Caspian Sea proper, which lies immediately to the west, by a narrow, rocky ridge having a very narrow opening in the rock through which the Caspian waters flow, cascading down into Garabogazköl, leading to the Turkmen language name of the bay, "Mighty Strait Lake". The water volume of the bay fluctuates seasonally with the Caspian Sea; at times it becomes a large bay of the Caspian Sea, while at other times its water level drops drastically.
Mazandaran is located on the southern coast of the Caspian Sea. It is bordered clockwise by Golestan, Semnan and Tehran provinces. This province also borders Qazvin and Gilan to the west.
Mazandaran province is geographically divided into two parts: the coastal plains, and the mountainous areas. The Alborz Mountain Range surrounds the coastal strip and plains of the Caspian Sea.
From the geographical point of view, Mazandaran province is divided into two parts i.e. coastal plain and the mountainous area. The Alborz Mountain Range like a huge wall has surrounded the coastal strip and plains of the Caspian Sea. Due to permanent sea breeze and local winds of the southern and eastern coasts of the Caspian Sea, sandy hills are formed, causing the appearance of a low natural barrier between the sea and plain.
There is often snowfall in the Alborz regions, which run parallel to the Caspian Sea's southern coast, dividing the province into many isolated valleys. The province enjoys a moderate, subtropical climate with an average temperature of 25 °C in summer and about 8 °C in winter. Although snow may fall heavily in the mountains in winter, it rarely falls at sea level.
Ecoregions:
The total wood production from these forests is estimated at . Golestan National Park and Shastkolateh forest watershed are located in Golestan Province), Mazandaran Province (the total area of the Hyrcanian forest is estimated at . From these forests, are used commercially, are protected and the rest are regarded as forest lands or over-used forests. The total of the forest woods used in this province is estimated at . The Kojoor, Dohezar and Sehezar forest watersheds are located in Mazandaran province.
The Elburz Range forest steppe ecoregion is an arid, mountainous 1,000-kilometer arc south of the Caspian Sea, stretching across northern Iran from the Azerbaijan border to near the Turkmenistan border. It covers and encompasses the southern and eastern slopes of the Alborz Mountains as well as their summits. The Caspian Hyrcanian mixed forests ecoregion, with its lush green mountainsides and plains that receive moisture from the Caspian Sea, forms this ecoregion's northern border. The vast Central Persian desert basin ecoregion forms its southern border. The Alborz range is composed of a granite core overlain with sedimentary rock including limestones, shales, sandstones, and tuffs. Metamorphic rocks such as schists, marbles, and amphibolite are also widely found. The climate is arid with annual precipitation varying from 150 mm to 500 mm, falling mostly as winter snow.
Eridania Lake is a theorized ancient lake with a surface area of roughly 1.1 million square kilometers. Its maximum depth is 2,400 meters and its volume is 562,000 km. It was larger than the largest landlocked sea on Earth, the Caspian Sea and contained more water than all the other martian lakes together. The Eridania sea held more than 9 times as much water as all of America's Great Lakes. The upper surface of the lake was assumed to be at the elevation of valley networks that surround the lake; they all end at the same elevation, suggesting that they emptied into a lake.
The Caspian Sea has numerous islands throughout, all of them near the coasts; none in the deeper parts of the sea. Ogurja Ada is the largest island. The island is 37km (23mi) long, with gazelles roaming freely on it. In the North Caspian, the majority of the islands are small and uninhabited, like the Tyuleniy Archipelago, an Important Bird Area (IBA), although some of them have human settlements.
The coastal artillery troops also play a very important role for the Navy. The geography of the Barents Sea, the Baltic Sea, the Black Sea and the Sea of Okhotsk as well as the Caspian Sea makes the deployment of shore-based, anti-ship systems in an area-deniying role very effective. They deploy K-300P Bastion-P supersonic AShM, 3M-54 Kalibr cruise subsonic AShM and A-222E Bereg-E 130mm coastal mobile artillery system as well as self-propelled surface-to-air missile systems.
It had a distinct coastline in former times, but since the 1990s, with higher Caspian Sea levels, the water penetrates inland through the neck of the bay producing waterlogged marshes. Located at the mainland end of the bay, the Kaydak Inlet cuts deep into the coast extending east and then southwards. Nowadays both the bay and the inlet are filled with Caspian Sea water. Currently there are oil fields in the area.
Owing to its special colour the Dead Kultuk is the bay which appears in early maps of the Caspian Sea as 'Blue Sea' ( in maps in that language). The area was mapped by Fedor Ivanovich Soimonov during the Caspian Expedition, which surveyed the Caspian Sea from 1719 to 1727, but was not accurately described until G. S. Karelin did so in 1832.
Lake Superior empties into Lake Huron via the St. Marys River and the Soo Locks. Lake Superior is the largest freshwater lake in the world in area (if Lakes Michigan and Huron are taken separately; "see Lake Michigan–Huron"), and the third largest in volume, behind Lake Baikal in Siberia and Lake Tanganyika in East Africa. The Caspian Sea, while larger than Lake Superior in both surface area and volume, is brackish; though presently isolated, prehistorically the Caspian has been repeatedly connected to and isolated from the Mediterranean via the Black Sea.
The history of the Caspian sea is divided into two parts: a Miocene stage, determined by tectonic events that correlate with the closing of the Tethys Sea, and a Pleistocene stage, that includes glaciation cycles and the creation of the present Volga River. During the first stage, the Tethys Sea had evolved into the Sarmatian Lake, that was created from the modern Black Sea and south Caspian, when the collision of the Arabian peninsula with Western Asia pushed up the Kopet Dag and Caucasus Mountains, setting definitive south and west boundaries to the Caspian basin. This orogeneic movement was continuous throughout the years, while Caspian was regularly disconnecting from the Black Sea. In the late Pontian, a mountain arch rose across the south basin and divided it in the Khachmaz and Lankaran Lakes (or early Balaxani). The period of restriction to the south basin was reversed during the Akchagyglian, when the lake expanded to more than three times its present area and established the first of a series of contacts with the Black Sea and with Lake Aral. A recession of the lake Akchagyl completed stage one.[31]
In the marine sequence of the Caspian basin, the Khvalynean layers are above the Late Khazarian ones (which date to the last interglacial period) and below the New Caspian (Holocene) deposits. They are separated from the Lower Khazarian series by continental Atelian layers synchronous to marine sediments from the Atelian basin. The level of the latter was below the present Caspian level—in other words, below sea level. In the Caspian Depression, the Khvalynean sediments occur primarily near the surface; younger still (and higher in the sequence) are the Holocene floodplain lacustrine and marine (New Caspian) sediments.