Blog – Page 8499

The hidden undersea continent of Zealandia underwent an upheaval at the time of the birth of the Pacific Ring of Fire.

Zealandia is a chunk of continental crust next door to Australia. It’s almost entirely beneath the ocean, with the exception of a few protrusions, like New Zealand and New Caledonia. But despite its undersea status, Zealandia is not made of magnesium- and iron-rich oceanic crust. Instead, it is composed of less-dense continental crust. The existence of this odd geology has been known since the 1970s, but only more recently has Zealandia been more closely explored. In 2017, geoscientists reported in the journal GSA Today that Zealandia qualifies as a continent in its own right, thanks to its structure and its clear separation from the Australian continent.

The Pueblo people created rock carvings in the Mesa Verde region of the Southwest United States about 800 years ago to mark the position of the sun on the longest and shortest days of the year, archaeologists now say.

Panels of ancient rock art, called petroglyphs, on canyon walls in the region show complex interactions of sunlight and shadows. These interactions can be seen in the days around the winter and summer solstices, when the sun reaches its southernmost and northernmost points, respectively, and, to a lesser extent, around the equinoxes — the “equal nights”— in spring and fall, the researchers said.