How wide is Cerro Blanco?
Cerro Blanco (volcano)
3.7mi
The Cerro Blanco complex is formed from pyroclastic flows extending from nested calderas. The Robledo caldera is heavily eroded and has assumed a semicircular shape. The rim of the Cerro Blanco caldera proper is well-preserved, with ash and block flows filling the interior.[2] Another theory holds that the northern Cerro Blanco and the southern Robledo calderas are part of one caldera with a minimum subsidence of 700 metres (2,300ft) and a dimension of 13 by 10 kilometres (8.1mi ×6.2mi).[4] The Cerro Blanco caldera is 6 kilometres (3.7mi) wide. On its southern rim, surrounded by ashfall deposits, lies the Holocene Cerro Blanco del Robledo lava dome ().[1] Some sources call the whole volcano Robledo and use Cerro Blanco to refer to the lava dome.[9] A third caldera north of Cerro Blanco is known as El Niño caldera[10] The whole volcanic complex is formed from lava domes, ignimbrites, ash and block flows and unconsolidated deposits. Cerro Blanco is the largest lava dome and has a debris collapse deposit on its northern side. A hydrothermally altered area in the middle of the caldera has been linked to phreatomagmatic activity. The El Escondido crater northeast of the caldera is 1.2 kilometres (0.75mi) wide and 40 metres (130ft) deep. It shows a dark colour and semiannular shape in satellite images and has been interpreted as a phreatic crater.[2] Other such craters are located within the caldera.[11] Aside from craters and calderas, there are about seven lava domes west of the caldera which are sources of block and ash flows and pyroclastic material; some of these predate the calderas, others formed after caldera formation and in some the relationship to the calderas is not clear.[12] The complex is located at the southwest end of a volcano-tectonic depression formed by local fault systems. These fault systems channel magma during eruptions; usually no eruption column is formed. The formation of the depression may be influenced by the emptying of magma chambers associated with the volcano.[4]