Ecuador's Tungurahua volcano is located east of the city of Ambato, the capital of Tungurahua Province. Tungurahua looms over the small adjacent city of Baños de Agua Santa, a popular tourist area.
Tungurahua has been erupting continuously since 1999, with only short periods of inactivity. The eruptions, sometimes daily, receive a great deal of attention in Ecuador, and the larger eruptions sometimes receive international attention. Many pictures have been published online of Tungurahua's fiery summit crater.
Most of Tungurahua's daily eruptions only spew a little volcanic ash into the air, or shower Tungurahua's summit with rock and lava. However, there are more serious events. The worst eruption since Tungurahua began her current period of activity in 1999 happened on August 16, 2006, and killed seven people. That 2006 eruption unleashed lahares, large dangerous flows of volcanic ash, water, and mud, that washed out drainages on the side of the mountain and completely destroyed large sections of the principal highway between Ambato and Baños. The highway has since been rebuilt, and a bus ride along it is a good way to see firsthand the effects of a lahar.
Some residents of Baños say that a religious statue of a virgin that overlooks town, as well as a ridge of rock which physically intercedes between Baños and Tungurahua's summit, protects them from Tungurahua's lava flows. However, most of those same residents fled to safety when a warning was issued during Tungurahua's most recent eruptive cycle. I'm sure they meant no disrespect to either the virgin or the ridge of rock.
I observed Tungurahua daily for the better part of a year from my home in Izamba, Ecuador. Tungurahua's eruptions impressed me as nothing else in my life has. Every morning I searched the sky for plumes of smoke and ash. I turned on the radio and listened attentively to reports from Ecuador's Geophysical Institute, detailing current levels of volcanic activity and expectations for the future. I went to the library and read books about Tungurahua and volcanism in Ecuador.
Tungurahua is located along the Cordillera Oriental (or Cordillera Real), a line of mountains formed by volcanic activity along the eastern slope of the Ecuadorian Andes. The Cordillera Oriental is also home to Ecuador's most photogenic volcano, Mount Cotopaxi, and most active volcano, the remote and mysterious Sangay. In addition to the volcanoes of the Cordillera Oriental, there are three other important groups of volcanoes in Ecuador, which are differentiated by location, age, and the type of eruptive material they eject. Tungurahua, Cotopaxi, and Sangay are andesitic strato-volcanoes, nearly perfect cones, and topped with glaciers, although Tungurahua's summit glacier, which was the smallest of the three, melted in 1999 and has not returned due to Tungurahua's continued volcanic activity.
The physical form of the volcanoes of the Cordillera Oriental, in terms of geologic time, is constantly changing. Tungurahua built herself up once, collapsed, built herself up a second time, then collapsed again. The scale of Tungurahua's two collapses was unimaginably large, the entire mountain literally blew herself out into nothingness twice. Tungurahua is now in the process of building herself up for the third time. At the start of this third buildup, some 2,300 years ago, Tungurahua extruded large lava flows composed almost exclusively of basic andesites. Beginning about 1,300 years ago, Tungurahua began to emit more pyroclastics, or projectile-type material, both andesites and dacites, at the beginning of each eruptive cycle, and flows of lava within the crater to terminate each cycle.
I have long thought Tungurahua the most impressive mountain in Ecuador, though I find that opinion difficult to justify to other people. There are higher mountains in Ecuador, historically more important mountains, mountains with more ice on them, and volcanos that have had more devastating eruptions. But Tungurahua has affected me as no other mountain, as I watched her brooding night after night in the twilight.
Geologists estimate that the current incarnation of Tungurahua is only half the size that she was before her last collapse, which happened 3,000 years ago. Immense as she is, Mama Tungurahua, as the indigenous people call her, is only a baby. Maybe that's the cause of my delirium over Tungurahua. (With apologies to Simon Bolivar, who felt delirium over Tungurahua's neighbor, Mount Chimborazo.) I sensed this latent power, this growth being called forth, when I watched Tungurahua in the setting sun, in the same way that I knew a miracle was taking place inside the monarch butterfly chrysalides that I watched in middle school. Mama Tungurahua may someday well be the Mama of them all.