East African Rift in the context of "Rift"

Ethiopia, officially the Federal Democratic Republic of Ethiopia, is a landlocked country located in the Horn of Africa region of East Africa. It shares borders with Eritrea to the north, Djibouti to the northeast, Somalia to the east, Kenya to the south, South Sudan to the west, and Sudan to the northwest. Ethiopia covers a land area of 1,104,300 square kilometres (426,400 sq mi). As of 2025, it has around 135 million inhabitants, making it the 14-most populous country. The national capital and largest city, Addis Ababa, lies several kilometres west of the East African Rift that splits the country into the African and Somali tectonic plates.

Anatomically modern humans emerged from modern-day Ethiopia. In 980 BC, the Kingdom of D'mt extended its realm over Eritrea and the northern region of Ethiopia, while the Kingdom of Aksum maintained a unified civilization in the region for 900 years. Christianity was embraced by the kingdom in 330, and Islam arrived by the first Hijra in 615. After the collapse of Aksum in 960, the Zagwe dynasty ruled the north-central parts of Ethiopia until being overthrown by Yekuno Amlak in 1270, inaugurating the Ethiopian Empire and the Solomonic dynasty, claimed descent from the biblical Solomon and Queen of Sheba under their son Menelik I. By the 14th century, the empire had grown in prestige through territorial expansion and fighting against adjacent territories; most notably, the Ethiopian–Adal War (1529–1543) contributed to fragmentation of the empire, which ultimately fell under a decentralization known as Zemene Mesafint in the mid-18th century. Emperor Tewodros II ended Zemene Mesafint at the beginning of his reign in 1855, marking the reunification and modernization of Ethiopia.

A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.

On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift, the Wells Gray-Clearwater volcanic field, and the Rio Grande rift in North America. Volcanism away from plate boundaries most likely arises from upwelling diapirs from the core–mantle boundary called mantle plumes, 3,000 kilometres (1,900 mi) deep within Earth. This results in hotspot volcanism or intraplate volcanism, in which the plume may cause thinning of the crust and result in a volcanic island chain due to the continuous movement of the tectonic plate, of which the Hawaiian hotspot is an example. Volcanoes are usually not created at transform tectonic boundaries where two tectonic plates slide past one another.

The Red Sea Rift is a mid-ocean ridge between two tectonic plates, the African plate and the Arabian plate. It extends from the Dead Sea Transform fault system, and ends at an intersection with the Aden Ridge and the East African Rift, forming the Afar triple junction in the Afar Depression of the Horn of Africa.

The Red Sea Rift was formed by the divergence between the African and Arabian plates. The rift transitioned from a continental rift to an oceanic rift. Magnetic anomalies suggest that the spreading rate on either side of the Red Sea is about 1 cm/year. The African plate has a rotation rate of 0.9270 degrees/Ma (million years), while the Arabian plate has a rotation rate of 1.1616 degrees/Ma.

The African plate, also known as the Nubian plate, is a major tectonic plate that includes most of the continent of Africa (except for its easternmost part) and the adjacent oceanic crust to the west and south. It also includes a narrow strip of Western Asia along the Mediterranean Sea, including much of Israel and Lebanon. It is bounded by the North American plate and South American plate to the west (separated by the Mid-Atlantic Ridge); the Arabian plate and Somali plate to the east; the Eurasian plate, Aegean Sea plate and Anatolian plate to the north; and the Antarctic plate to the south.

Between 60 million years ago and 10 million years ago, the Somali plate began rifting from the African plate along the East African Rift. Since the continent of Africa consists of crust from both the African and the Somali plates, some literature refers to the African plate as the Nubian plate to distinguish it from the continent as a whole.

A fissure vent, also known as a volcanic fissure, eruption fissure or simply a fissure, is a linear volcanic vent through which lava erupts, usually without any explosive activity. The vent is often a few metres wide and may be many kilometres long. Fissure vents can cause large flood basalts which run first in lava channels and later in lava tubes. After some time, the eruption tends to become focused at one or more spatter cones. Volcanic cones and their craters that are aligned along a fissure form a crater row. Small fissure vents may not be easily discernible from the air, but the crater rows (see Laki) or the canyons (see Eldgjá) built up by some of them are.

The dikes that feed fissures reach the surface from depths of a few kilometers and connect them to deeper magma reservoirs, often under volcanic centers. Fissures are usually found in or along rifts and rift zones, such as Iceland and the East African Rift. Fissure vents are often part of the structure of shield volcanoes.