Ozone depletion as the International Day for the Preservation of the Ozone Layer, or "World Ozone Day", to commemorate the signing of the Montreal Protocol on that date in 1987. Ozone depletion Ozone depletion describes two related events observed since the late 1970s: a steady lowering of about four percent in the total amount of ozone in Earth's atmosphere (the ozone layer), and a much larger springtime decrease in stratospheric ozone around Earth's polar regions. The latter phenomenon is referred to as the ozone hole. There are also springtime polar tropospheric ozone depletion events in addition to these stratospheric events. The main
The Layer Monument The Layer Monument The Layer monument is an early 17th-century polychrome marble mural monument (320 × 350 cm) erected to the memory of the lawyer Christopher Layer (1531–1600), and located in the Church of Saint John the Baptist, Maddermarket, Norwich. Its inscription is in Latin, and reads in translation: The monument is notable on two accounts, firstly, its four figurines housed in its two columns, "Pax" and "Gloria", "Vanitas" and "Labor", are relatively rare examples of Northern Mannerist sculpture extant in Britain; secondly, these four figurines exemplify how, during the era of Elizabeth I, Christian iconography occasionally integrated symbolism which