geology

Pacific nation Tuvalu has grown by 73 hectares over 40 years

“The tiny Pacific nation of Tuvalu – once thought to be under threat from rising sea levels – has grown the size of California’s Disneyland over the past 40 years. It’s mostly thanks to waves dumping extra sediment, sand and gravel on shore lines, according to research by Auckland University scientists. The study, published in the Nature Communications journal on Friday, was the first in-depth look at how much each of Tuvalu’s 101 islands have changed over the decades.”

Tags: Oceania, water, coastal, environment, physical, geomorphology, erosion, geology, landforms.

Source: www.stuff.co.nz

July 2, 2018 0

See the Strange, Beautiful Landscapes Revealed by Lasers

“Geospatial technologies unearth a world hidden beneath the lush forests of the Pacific Northwest.”

If you were to strip a forest of all its vegetation, what would you see? To find out, Washington state’s government is using airplanes equipped with LIDAR technology to scan the state’s heavily-forested ground. What’s being revealed beneath the trees is a spectacular and strange landscape of hidden geology. Old landslides, abandoned river channels, ancient lava flows, and the tracks of glaciers are suddenly visible in stark relief. Tracking the altitude and location of a plane with GPS while it scans the ground with LIDAR yields a highly precise digital elevation map of the Earth’s surface created out of the billions of laser pulses. By uncovering the debris from old landslides, LIDAR can show where future slides may occur.

Tags: geomorphology, remote sensing, geology, physical.

Source: news.nationalgeographic.com

April 2, 2018 0

The Edge of the Plates

“Tomales Bay lies about 50 kilometers (30 miles) northwest of San Francisco, along the edges of two tectonic plates that are grinding past each other. The boundary between them is the San Andreas Fault, the famous rift that partitions California for hundreds of miles. To the west of the Bay is the Pacific plate; to the east is the North American plate. The rock on the western shore of the Bay is granite, an igneous rock that formed underground when molten material slowly cooled over time. On the opposite shore, the land is a mix of several types of marine sedimentary rocks. In Assembling California, John McPhee calls that side “a boneyard of exotica,” a mixture of rock of ‘such widespread provenance that it is quite literally a collection from the entire Pacific basin, or even half of the surface of the planet.'”

Tags: geomorphology, remote sensing, tectonics, geology, California, coastal, physical.

Source: earthobservatory.nasa.gov

September 9, 2017 0

Is Zealandia the eighth continent?

“A group of geologists say they’ve enough evidence to confirm the existence of a new continent. Writing in the journal of the Geological Society of America, the group named the eighth continent ‘Zealandia.’ Scientists argue for an 8th continent, Zealandia, in the Geological Society of America.”

Source: www.youtube.com

What makes a continent a continent? There is no set definition of a continent. Some consider cultural groupings and would consider Europe as a separate continent from Asia as a consequence. Geologists consider continental shelves as the defining characteristics of a continent and thus consider Eurasia to be just one continent. We are so accustomed to seeing the coastlines, but if the ocean were drained, we’d see Zealandia and it’s ancient confidential shelf–but don’t expect all the continental maps in elementary schools to change anytime soon.

Questions to Ponder: Does human geography or physical geography determine what you consider a continent? How come?

Tags: physical, tectonics, geology, regions, Oceania.

April 4, 2017 0

Why Is Greenland an Island but Australia a Continent?

“Why is Australia a continent and Greenland is not? Even though Australia is the smallest of the accepted continents, Australia is still more than 3.5 times larger than Greenland. There has to be a line in the sand between small continent and the world’s largest island and traditionally that line exists between Australia and Greenland. Geologically, Australia lies on its own major tectonic plate while Greenland is part of the North American plate.”

Source: www.thoughtco.com

I’m sharing this link for two reasons.

To help resolve the confusion as to why Greenland the world’s largest island but Australia gets to be the smallest continent. The main reason is all about the continental shelf and not the coastline–Greenland is connected to North America to the continental shelf while Australia has its own shelf.
I know many of you have been fans of Matt Rosenberg’s online resources over the years. If you have lost track of him, he is continuing to share geographic information on ThoughtCo.

Tags: Greenland, Australia, geology.

March 9, 2017 0

New Zealand quake lifted seabed by 2m

The 7.8 magnitude earthquake that hit New Zealand’s South Island lifted up the seabed by two metres, pushing it above the ocean’s surface.

Source: www.9news.com.au

Plates on the Earth’s crust typically move forward at very slowly (about the same speed as the fingernail growth). While that is the usual, plates snag along the edges and pressure can build over the years, only to lead to explosive, quick changes like happened recently in New Zealand. This complex series of tremors has people disconnected as much of the physical infrastructure has be damaged.

Tags: New Zealand, physical, tectonics, transportation, geology, geomorphology.