Colima is the most active volcano in Mexico having erupted more than 40 times since the mid 1500s and in my opinion is among the most beautiful on the decade volcano list.
The Colima Volcanic Complex consists of three peaks. The currently active peak, named Volcan de Colima (the decade volcano) which stands at ~3850 m and is also known as Volcano de Fuego. The older but taller Nevado de Colima (~4320 m) sits to the North of its younger counterpart. The eroded Cátaro peak (~2500 m) which lies further to the North still. Colima is located in the Trans-Mexican Volcanic Belt and is the result of the subduction of the Cocos and Rivera tectonic plates beneath the North American counterpart.
The current eruptive period at Colima has been ongoing since 1997 with the main type of explosion which occurs here Vulcanian in origin. Vulcanian eruptions are generally described as short lived bursts which produce an ash/steam column which can range in height between hundreds of metres or generally to ~10 km. Effusive activity also occurs at Colima with lava flows occuring commonly throughout its history. Generally the eruptions are small in scale however larger eruptions (up to VEI 4) have occurred in the past which have destroyed the summit area
Colima is currently monitored by the Colima Volcano Observatory. For a panorma of the observatory visit this link. The website of the Observatory is available here, where you can find webcams, photos and more detailed information of the volcano. Due to it's location and easy access Colima has become one of the most studied volcanoes and this is in part due to the excellent management and work done at and by the University of Colima.
Please feel free to comment on this or any of my posts, I am open to suggestions and would love to have a little interaction with readers.