Popocatepetl

Figure 1 Grey Scale Infrared	Figure 2 Visible

Our gallery presents coincident infrared (Figure 1) and visible (Figure 2) images of Mexico taken on March 12, 1996 at 1936 UTC from NOAA 14 (one of two currently operating NOAA polar orbiting satellites). Throughout much of March, 1996, Popocatepetl was in a relatively steady-state eruptive phase with short-duration ash emissions occurring 4-6 times per day. As with single channel images from the GOES satellites, the ash plume from the erupting Mount Popocatepetl is not as easily detected as might be expected, but can be spotted near the center of the image. The enlarged images available by clicking on the images are labeled.

On December 21, 1994, Popocatepetl Volcano, approximately 65 kilometers east of Mexico City underwent a significant eruption for the first time since 1921. An ash plume deposited ash at Puebla, 45 kilometers east of the summit. On December 26, an even larger eruption pushed an ash cloud to a height of 22,000 feet.

After being quiet during 1995, Popocatepetl again erupted on March 5, 1996 and continued throughout the month. The March, 1996 eruption was the first significant volcanic event in which GOES-8 multi-channel imagery for volcanic eruptions was tested and evaluated. The National Environmental Satellite, Data, and Information Service's Satellite Analysis Branch issued hazard alert messages, and production of graphical depictions of the volcanic ash from Popocatepetl was begun on March 10. In the past, SAB used single channel infrared and visible imagery, but for this case the ash was often invisible on satellite images. Two split-window techniques were successfully tested and implemented on March 13. From then through 14Z on April 1, eighty-three alert messages and forty-three graphics were produced.

On March 29, 1996 a lava dome was noted building near the center of a small inner crater. By April 29, 1996, this dome was larger than the dome produced in the 1920's. On April 30, an explosion at the dome spewed ash to the northeast, and on May 2, 1996, five mountain climbers were found dead on the slopes of the volcano.

After a small ash cloud was ejected on October 28, 1996, the most intense eruption to date occurred on April 17, 1997. In that event, and in another one on May 11-13, 1997, small forest fires were begun near the volcano's summit. Ash fell all the way to the Gulf of Mexico in the May event.

So far, no major damage has been done by the volcano, but a close watch is being kept on its activities. As of August, 1997, Popocatepetl is still awake, and may periodically spew ash or lava.