- Shield volcano -

Mauna Loa
Mauna Loa shield volcano, Hawai'i

Brief explanation:

Shield volcanoes are volcanoes that mainly erupt fluid (usually basaltic) lava flows that are able to travel over long distances and thus construct over time broad, gentle slopes. They are called shield volcanoes, because they resemble the shape of a warriors' shield.
While stratovolcanoes, the other major morphological type of volcanoes, are representative for most subduction-type volcanoes, shield volcanoes are typically formed by basaltic hot-spot volcanoes such as on Hawaii (e.g. Mauna Loa, Kilauea). Among these are the largest mountains on earth.

Mauna Loa volcano on the Island of Hawai`i, the classic shield volcano, is the largest volcano on Earth. With an elevation of 4,170 m above sea level, its long submarine flanks descend to the sea floor an additional 5 km, and the sea floor in turn is depressed by Mauna Loa's great mass another 8 km. This makes the volcano's summit about 17 km (56,000 ft) above its base! The volcano is constructed of an estimated 80,000 km3 of basalt! For more information about Mauna Loa, see the USGS Hawaiian Volcano Observatory website. (Abbreviated from USGS Photoglossary).

The near horizontal lava flows of the Skaros volcano are remnants of an old shield volcano on Santorini, constructed between approx. 80 and 20 ka and partly destroyed by repeated caldera collapse.
Rootless lava shields such as the one in the middle ground of the l photo (W of Kilauea's currently active vent Pu'u O'o on the E rift-zone of Kilauea volcano, Hawaii) are not independent volcanoes as such, but they resemble miniature shield volcanoes. Both get their flat shapes by fluid lava flows accumulating above each other.