July 2021 – Geobites

July 29, 2021July 28, 2021

Throwing Earth Off Balance: Evidence Grows that Our Planet is Heating Up Faster than in the Past

Feature image: A satellite looks down at the surface of Earth. Image from Unsplash

Paper: Satellite and Ocean Data Reveal Marked Increase in Earth’s Heating Rate

Authors: N. G. Loeb, G. C. Johnson, T. J. Thorsen, J. M. Lyman, F. G. Rose, and S. Kato

At the most fundamental level, what causes climate change? Simply put, climate change is a symptom of an energy imbalance with more energy coming into Earth’s atmosphere than is able to go out. This imbalance drives changes in our climate system that scientists around the world study, including warming temperatures, rising sea levels, melting glaciers, and coral reef bleaching. Using two different kinds of observational data, a recent study has found evidence that the energy imbalance is increasing, which suggests climate change will only worsen.

July 22, 2021July 22, 2021

Breaking the ice — Climate systems during Snowball Earth

Featuring image: modern sea ice at Antarctica. Denis Luyten (Wikimedia Commons), public domain (CC0).

Paper: Orbital forcing of ice sheets during snowball Earth

Authors: R. N. Mitchell, T. M. Gernon, G. M. Cox, A. R. Nordsvan, U. Kirscher, C. Xuan, Y. Liu, X. Liu, X. He

When you think about the Earth, you might imagine a blue and green globe orbiting the Sun. But the face of Earth has changed significantly over its life time and in the past, there were times when the Earth resembled more to a frozen, white snowball. Geologists, studying the climate during these cold epochs, found a connection between climate conditions in frozen oceans and variations of Earth’s orbit.

Continue reading “Breaking the ice — Climate systems during Snowball Earth”

July 14, 2021July 14, 2021

A New Paradigm in Decision Making?

Paper: Quantifying Topological Uncertainty in Fractured Systems using Graph Theory and Machine Learning

Authors: Gowri Srinivasan, Jeffrey D. Hyman, David A. Osthus, Bryan A. Moore, Daniel O’Malley, Satish Karra, Esteban Rougier, Aric A. Hagberg, Abigail Hunter & Hari S. Viswanathan

Geophysics problems are as difficult as Nobel Prize-winning physics problems.
Dr. Jérõme A.R. Noir

This quote from Dr. Jérõme Noir has stayed with me throughout my career. The idea: while physicists face extreme math, but also have extremely precise data for unknown phenomena, geoscientists must find vital solutions for known phenomena using just a few data points on a planet. With very little data, how can complex problems in geoscience be solved? And, how do we assess the risk of being wrong? An uncertainty quantification framework recently developed by researchers at Los Alamos National Lab uses machine learning to help geoscientists arrive at quality decisions using limited data.

July 7, 2021July 7, 2021

One of the Moon’s most prominent features is older than we thought

Featured image: the Moon by Pedro Lastra on Unsplash

Paper: Černok, A., White, L.F., Anand, M. et al. Lunar samples record an impact 4.2 billion years ago that may have formed the Serenitatis Basin. Commun Earth Environ 2, 120 (2021). https://doi.org/10.1038/s43247-021-00181-z

About 4 billion years ago, the inner Solar System fell prey to an apocalyptic assault by asteroids. These asteroids slammed into the terrestrial planets—Mercury, Venus, Earth, Mars—and the Moon, leaving behind the scars and basins that make up the planets’ landscapes today. This attack, called the Large Heavy Bombardment, helps explain the genesis of a majority of the formations decorating the inner planets of the Solar System. Previous dating of Moon rocks helped pindown the occurrence of the Bombardment somewhere around 3.8 billion years ago. While this window of time is widely accepted in the planetary science community, one of the Moon’s most iconic features, the Serinatits Basin, might poke a hole in it.

July 1, 2021July 1, 2021

Buried treasure in the oceans: chemistry of small deep-sea crystals hints at past carbon cycling

Featured image: Crystals of the mineral barite from the deep ocean (Adapted from Kastner (1999)). These crystals precipitated in ocean sediments and are about 9 million years old, similar in age to some of the barite samples from the study discussed here.

Paper: A 35-million-year record of seawater stable Sr isotopes reveals a fluctuating global carbon cycle

Authors: Adina Paytan, Elizabeth M. Griffith, Anton Eisenhauer, Mathis P. Hain, Klaus Wallmann, Andrew Ridgwell

What do ancient ocean sediments and the walls around x-ray machines have in common? One possible answer? Sometimes the mineral barite is an important part of both! Barite (or barium sulfate) is able to block gamma and x-ray emissions, and therefore is sometimes used in high-density concrete in hospitals and laboratories. In the deep ocean, tiny crystals of barite naturally accumulate on the seafloor over time, particularly in regions ideal for this mineral formation where many decaying remains of organisms sink to the seafloor. The chemistry of this barite can give scientists clues into Earth’s past, which is what Adina Paytan and her colleagues did in this study.