Monday, February 13, 2023

Pangaea, Rodinia, Columbia, and Kenorland


Scientists theorize that supercontinents have formed in cycles throughout Earth's history. Pangaea was the most recent one, and it broke up approximately 200 million years ago. Some scientists believe we are in the middle of the formation of a new supercontinent that will include the mountains formerly known as the Mediterranean Sea

This should not create anxiety. The movement of Earth's plates is very slow. It will be another 50 million years before the Mediterranean Sea disappears as the African Plate and the Eurasian plate join.

The Pangaea supercontinent existed during the late Paleozoic and early Mesozoic eras. Pangaea is the most recent supercontinent to have existed and the first to be reconstructed by geologists.

Rodinia (Russian родина, meaning "motherland" or "birthplace") was a Neoproterozoic supercontinent that assembled 1.1–0.9 billion years ago and broke up 750–633 million years ago. Rodinia's continental fragments reassembled to form Pannotia 633–573 million years ago (shown below). 

Pannotia was named by Powell (1995, University of Western Australia) based on the term "Pannotios" proposed by Stump in 1987 for "the cycle of tectonic activity common to the Gondwana continents that resulted in the formation of the supercontinent."

Another of Earth's supercontinents is called Columbia (Nuna or Hudsonland) and is thought to have existed approximately 2,500 to 1,500 million years ago in the Paleoproterozoic Era (from 2,500 to 1,600 million years ago). Zhao et al. 2002 proposed that the assembly of the supercontinent Columbia was completed by global-scale collisional events during 2.1–1.8 billion years ago. Other sources give 1,820–1,350 million years ago.

Columbia consisted of proto cratons that made up the cores of the continents of Laurentia, Baltica, Ukrainian Shield, Amazonian Shield, Australia, and possibly Siberia, North China, and Kalaharia as well.

Kenorland was one of the earliest known supercontinents on Earth. It is thought to have formed during the Neoarchaean Era c. 2.72 billion years ago by the accretion of Neoarchaean cratons and the formation of new continental crust.

Tuesday, February 7, 2023

2023 "Year of Open Science"

In a time when many distrust Science or feel that their input is neglected, NASA proposes a corrective.

NASA has declared 2023 as the Year of Open Science to celebrate the benefits and successes of open science and to inspire more scientists to adopt open science practices. NASA's Year of Open Science is part of the five-year Transform to Open Science (TOPS) mission and the Open Source Science Initiative (OSSI). TOPS is an ambitious plan to accelerate open science practices and major scientific discoveries by increasing understanding and adoption of open science practices and broadening participation by historically excluded communities. 

In 2023, TOPS will release an introductory open science curriculum, engage with historically underrepresented groups, and develop incentives for open science practices. 

The success of the Year of Open Science will be driven by collaborations with individuals, teams, and organizations who are ready to transform the culture of scientific research into one that celebrates openness and inclusion.

Strategic Objectives

Open Science creates more advanced and inclusive research faster, builds a more just and equitable world, and ensures that minds from all walks of life can participate in science. TOPS is NASA’s ambitious plan to accelerate open science practices. It’s a 5-year journey that will: 

Accelerate major scientific discoveries.

Broaden participation by historically excluded communities.

Increase understanding and adoption of open science principles and techniques.

Open Science will broaden participation, increase accessibility to knowledge, and embrace new technologies that can respond to these changes at scale. 

If your organization wishes to create an open science infrastructure, TOPS will show you how.

Monday, January 30, 2023

Dr. Judith Curry Deserves a Fair Hearing


Dr. Judith Curry is a true climatologist. She once headed the department of earth and atmospheric sciences at the Georgia Institute of Technology, until she gave up on the academy so that she could express herself independently. She once told a journalist, “Independence of mind and climatology have become incompatible.”

She added, "Climatology has become a political party with totalitarian tendencies,” she charges. “If you don’t support the UN consensus on human-caused global warming, if you express the slightest skepticism, you are a ‘climate-change denier,’ a stooge of Donald Trump, a quasi-fascist who must be banned from the scientific community.”

The climate models used by scientists working for the United Nations cannot explain why the climate suddenly cooled between 1950 and 1970, giving rise to widespread warnings about the onset of a new ice age.

Curry notes that between 1910 and 1940, the planet warmed during a climatic episode that resembles our own, down to the degree. The warming cannot be blamed on CO2 emissions because the carbon-dioxide emissions from burning fossil fuels were relatively small in those years. Curry says, “almost half of the warming observed in the twentieth century came about in the first half of the century, before carbon-dioxide emissions became large.”

Speaking of climate changes, she points to natural factors, of which there are many. These factors reveal far greater complexity than is generally acknowledged by global warming alarmists.

The following organizations are in agreement that climate changes: the U.S. National Academy of Sciences, the National Academies of more than 30 other countries, the American Association for the advancement of science (AAAS), the American Meteorological Society (AMS), The American Institute of Physics (AIP), The Geological Society of America (GSA), The American Physical Society (APS), and the American Geophysical Union (AGU).

However, among the scientists in these organizations there is a range of positions as to which factors contribute most to warming. All tend to agree that solar radiance and Earth-Sun geometry are very significant. Yet we hear about this less than we hear about the danger of CO2 emissions from fossil fuel energy sources.

Earth's climate varies from region to region and from age to age. Therefore, it is misleading to speak of "climate change". Instead, we should speak of "climate changes" over vast periods of time. The Pleistocene glacial epoch (2,600,000-11,700 years ago) saw substantial variations in the extent of glaciers and ice sheets. These variations were driven by changes in the distribution of solar radiation across Earth’s surface. The insolation pattern is strongly affected by the geometry of Earth’s orbit around the Sun and by the orientation, or tilt, of Earth’s axis relative to the direct rays of the Sun.

Worldwide, the most recent glacial period, or ice age, culminated about 21,000 years ago in what is called the Last Glacial Maximum (LGM). During this time, continental ice sheets extended well into the middle latitude regions of Europe and North America, reaching as far south as present-day London and New York City. Global annual mean temperature appears to have been about 4–5 °C (7–9 °F) colder than in the mid-20th century.

The Sahara was once wet, and with on-going reforestation projects and changes in monsoons, it will likely be wet again.

The Botswanan basin in southern Africa was once a sea, filled by water from the Angolan Highlands. Thousands of stoneage tools have been found there. 

At its peak, Mega Lake Chad covered more than 400,000 square kilometers (150,000 square miles), making it the largest lake on Earth today.

Researchers identified two distinct environments at the South Pole at the close of the Permian Period. There was a warm rainforest with tree-ferns, palm trees, and baobab trees at the lower elevations, and a cooler mountainous region dominated by beech trees and conifers.

NASA bases climate change on a 136-year record. According to NASA, 16 of the 17 warmest years in the 136-year record all have occurred since 2001, with the exception of 1998. What happened to make 1998 different? This marked the completion of Earth's axial precession, a cycle of about 25,800 years (Earth's Great Year). Obviously, we have no climate records going back that far.

In the cycle of Earth’s Great Year, the line off the North Pole axis (extending toward Polaris) scribes a complete circle in the heavens about every 25,800 years. A complete cycle takes between 25,000 and 28,000 years, depending on the amount of Earth's wobble. One cycle is Earth’s Great Year. Climate and atmospheric changes appear to become more acute toward the end and beginning of a new year.

Judith Curry is not alone in her consideration of natural causes. In June 2013, Dr. Roy W. Spencer wrote, "Hundreds of millions of dollars that have gone into the expensive climate modelling enterprise has all but destroyed governmental funding of research into natural sources of climate change. For years the modelers have maintained that there is no such thing as natural climate change…yet they now, ironically, have to invoke natural climate forces to explain why surface warming has essentially stopped in the last 15 years!"

Monday, January 16, 2023

Self-Healing Concrete


A section of the First Century BC Roman wall of Empuries (Ampurias) in Spain. 
The base of the wall was made of calcareous rock while the upper portion is of Roman concrete (opus caementicium).  Photo by Mark Cartwright, Creative Commons

Cement is a human-made conglomerate comprised of sand and gravel aggregates with calcined lime and clay. It is mixed with water to form mortar or mixed with sand, gravel, and water to make concrete. Concrete is a mixture of broken stone or gravel, sand, and cement. In ancient times concrete often contained crushed seas shells.

Cement-matrix composites include concrete (containing coarse and fine aggregates), mortar (containing fine aggregate, but no coarse aggregate), and cement paste (containing no aggregate, whether coarse or fine).

The ancient Romans built extremely durable sea walls using a concrete made from lime and volcanic ash to bind with rocks. Rather than eroding in the presence of sea water, the material gained strength from the exposure. Scientists have discovered that elements within the volcanic material reacted with sea water to strengthen the construction.

“Contrary to the principles of modern cement-based concrete, the Romans created a rock-like concrete that thrives in open chemical exchange with seawater,” reports Marie Jackson (University of Utah) in the journal American Mineralogist.

Mixing the concrete with limestone-producing bacteria allowed for cracks to self-heal. The bacteria, either Bacillus pseudofirmus or Sporosarcina pasteurii, are found in highly alkaline lakes near volcanoes, and are able to survive for up to 200 years without oxygen or food. They are activated when they come into contact with water. They then use the calcium lactate as a food source, producing limestone that closes up the cracks.

Related reading: Ancient Roman Concrete was Incredibly Strong

Tuesday, January 3, 2023

Massive Fish Nest Colony



Off the coast of Antarctica, icefish congregate in a deep breeding colony. Some 60 million nests of Jonah’s icefish (Neopagetopsis ionah) stretch across at least 240 square kilometers of seafloor. 

Jonah’s icefish create circular nests with hard rock centers where the fish can lay over 1,000 eggs. Nest-building species of fish were known to gather in the hundreds. Many fish create nests, from freshwater cichlids to artistically inclined pufferfish, but an abundant food supply and a zone of warm water have drawn the exceptionally large group of Jonah's Icefish.

Deep sea biologist Autun Purser of the Alfred Wegener Institute in Bremerhaven, Germany, and colleagues discovered the massive colony in 2021 while on a research cruise in the Weddell Sea, located between the Antarctic Peninsula and the main continent.

Read more here.