This long-buried glacier ice is at least 770,000 years old

Arctic: A region that falls within the Arctic Circle. The edge of that circle is defined as the northernmost point at which the sun is visible on the northern winter solstice and the southernmost point at which the midnight sun can be seen on the northern summer solstice. The high Arctic is that most northerly third of this region. It’s a region dominated by snow cover much of the year.

atmosphere: The envelope of gases surrounding Earth, another planet or a moon.

climate: The weather conditions that typically exist in one area, in general, or over a long period.

climate change: Long-term, significant change in the climate of Earth. It can happen naturally or in response to human activities, including the burning of fossil fuels and clearing of forests.

epoch: (in geology) A span of time in the geologic past that was shorter than a period (which is itself, part of some era ) and marked when some dramatic changes occurred.

fossil: Any preserved remains or traces of ancient life. There are many different types of fossils: The bones and other body parts of dinosaurs are called “body fossils.” Things like footprints are called “trace fossils.” Even specimens of dinosaur poop are fossils. The process of forming fossils is called fossilization.

glacier: A slow-moving river of ice hundreds or thousands of meters deep. Glaciers are found in mountain valleys and also form parts of ice sheets.

ice age: Earth has experienced at least five major ice ages, which are prolonged periods of unusually cold weather experienced by much of the planet. During that time, which can last hundreds to thousands of years, glaciers and ice sheets expand in size and depth. The most recent ice age peaked 21,500 years ago, but continued until about 13,000 years ago.

interglacial: An adjective that responds to a period of relatively mild climate that exists between two successive ice ages. Earth is now in an interglacial period, one that began roughly 11,700 years ago.

magnetic pole: Each end of a bar magnetic is known as its pole. They’re designated north and south poles and are those parts of the magnetic where its force (pull) is strongest. Like poles (north or south) between any two magnets will repel each other; unlike poles will attract. Earth also has a magnetic field, and at the ends of each (roughly where the planet’s North and South Poles exist) will be its geomagnetic poles.

matter: Something that occupies space and has mass. Anything on Earth with matter will have a property described as “weight.”

mineral: Crystal-forming substances that make up rock, such as quartz, apatite or various carbonates. Most rocks contain several different minerals mish-mashed together. A mineral usually is solid and stable at room temperatures and has a specific formula, or recipe (with atoms occurring in certain proportions) and a specific crystalline structure (meaning that its atoms are organized in regular three-dimensional patterns).

Nunavut: A region of mostly frozen, snow-covered land in northern Canada. It separated from the nation’s Northwest Territories in April 1999, becoming the newest Canadian territory. It runs from Baffin Bay and the Labrador Sea in the east to the Northwest Territories in the West. It sits north of the provinces of Manitoba and Saskatchewan. Comprising almost 20 percent of Canada, it is bigger than the U.S. state of Alaska, yet had fewer than 25,000 inhabitants when it was established. Most of its residents are native peoples, known as the Inuit. Nunavut means “our land” in the Inuit language.

organic: (in chemistry) An adjective that indicates something is carbon-containing; also a term that relates to the basic chemicals that make up living organisms.

permafrost: Soil that remains frozen for at least two consecutive years. Such conditions typically occur in polar climates, where average annual temperatures remain close to or below freezing.

Pleistocene: The earlier epoch of the Quaternary Period. It ranged from 2.6 million to 11,700 years ago. The term can also refer to rocks that from this period. During this time, periods of Ice Ages and interglacial warming occurred. The mammoth was one of the largest land animals from this time.

poles: (in Earth science and astronomy) The cold regions of the planet that exist farthest from the equator; the upper and lower ends of the virtual axis around which a celestial object rotates.

radiocarbon dating: Short for radioactive-carbon dating or simply carbon dating. A way to measure the age of organic materials — ones containing carbon. Carbon-14, a weakly radioactive isotope, forms in Earth’s upper atmosphere as cosmic rays hit nitrogen atoms. This carbon joins with oxygen to form carbon dioxide, which living organisms take up and incorporate in their tissues. When those organisms die, they stop exchanging carbon with the environment and the share of the carbon-14 isotope starts to fall at a constant rate (one set by the law of radioactive decay). By measuring the share of carbon-14 in the organism’s remains, scientists can determine how long ago it died.

remnant: Something that is leftover — from another piece of something, from another time or even some features from an earlier species.

resilient: (n. resilience) To be able to recover fairly quickly from obstacles or difficult conditions. (in materials) The ability of something to spring back or recover to its original shape after bending or otherwise contorting the material.

sediment: Material (such as stones and sand) deposited by water, wind or glaciers.

translucent: The property of letting light through, but not being transparent. Usually, things viewed through a translucent material (such as frosted window glass) appear as hazy shapes with no detail.