Today (U.S. TV program) debuted, it was seen live only in the Eastern and Central time zones, broadcasting for three hours each morning but seen for only two hours in each time zone. Since 1958, "Today" has been tape-delayed for the five other U.S. time zones (Central, Mountain, Pacific, Alaska and Hawaii–Aleutian). Partly to accommodate host Dave Garroway's declining health, the program ceased live broadcasts in the summer of 1958, opting instead to broadcast an edition taped the previous afternoon. The experiment, which drew criticism from many sides, ended when John Chancellor replaced Garroway in July 1961. "Today" was a two-hour program for many
Aleutian subduction zone rocks, with trace amounts of Paleozoic rocks intruded by Mesozoic batholiths. Most of the Aleutian Islands are composed of sedimentary rocks from granitic and metamorphic rocks from Oligocene-Miocene. There are Quaternary volcanoes on the north of the Aleutian Islands structural axis, which is composed of andesite mostly, mixed with olivine basalt to rhyolite. The eastern Aleutian volcanoes have more silicic magma while the western Aleutian arcs lack the sial magma. The Aleutian Trench formation is associated with the subduction of the Pacific Plate beneath the North American plate. The horizontally-curved shape of the trench is due to the change in