Kiloannus in the context of Synodic day

A millennium (pl. millennia or millenniums) is a period of one thousand years, one hundred decades, or ten centuries, It is also sometimes called a kiloannum (ka) or kiloyear (ky).

Normally, the word is used specifically for periods of a thousand years that begin at the starting point (initial reference point) of the calendar in consideration and at later years that are whole number multiples of a thousand years after the start point. The term can also refer to an interval of time beginning on any date. Millennia sometimes have religious or theological implications (see millenarianism).

Deglaciation is the transition from full glacial conditions during ice ages, to warm interglacials, characterized by global warming and sea level rise due to change in continental ice volume. Thus, it refers to the retreat of a glacier, an ice sheet or frozen surface layer, and the resulting exposure of the Earth's surface. The decline of the cryosphere due to ablation can occur on any scale from global to localized to a particular glacier. After the Last Glacial Maximum (ca. 21,000 years ago), the last deglaciation begun, which lasted until the early Holocene. Around much of Earth, deglaciation during the last 100 years has been accelerating as a result of climate change, partly brought on by anthropogenic changes to greenhouse gases.

The previous deglaciation took place from approximately 22 ka until 11.5 ka. This occurred when there was an annual mean atmospheric temperature on the earth that increased by roughly 5 °C, which was also accompanied by regional high-latitude warming that exceeded 10 °C. This was also followed by noteworthy deep-sea and tropical-sea warming, of about 1–2 °C (deep-sea) and 2–4 °C (tropical sea). Not only did this warming occur, but the global hydrological budget also experienced noticeable changes and regional precipitation patterns changed. As a result of all of this, the world's main ice sheets, including the ones located in Eurasia, North America and parts of the Antarctic melted. As a consequence, sea levels rose roughly 120 metres. These processes did not occur steadily, and they also did not occur at the same time.

This is a sortable list of large eruptions that occurred between 11.7 Ka and 450+ Ma. Uncertainties as to dates and tephra volumes are not restated, and references are not repeated. The inclusion criteria here only covers entries with a Volcanic explosivity index (VEI) of 5 or greater. The given values for events in the Miocene epoch sometimes lack references, and are given as VEI-equivalent, as an estimate of the erupted tephra volume.