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geology

This tag is associated with 16 posts

Best of both worlds: stromatolites of the intertidal zone

Did you know that the earliest form of life on Earth can still be found today? Read more to find out how researchers studied ancient formations called stromatolites growing within the intertidal zone of Cape Elizabeth, South Africa, and how salinity and nutrients influence these rare structures.

Red dead algae

Life on earth has been evolving for a long time – billions of years! The timing of when different kinds of life developed is controversial, but can tell us about the conditions of earth in the past. A group of scientists in Sweden looked at ancient fossils from India, and found what they describe as red algae. This is important because at 1.6 billion years old (that’s 1,600,000,000 years) this is the oldest fossil of this type of algae described to date. These red algae fossils are also much older than most biological models said they should be. This could mean that more types of organisms have been around longer than we thought!

Mountains vs. Climate, Recorded in Marine Sediment

Mountain ranges can actively evolve with Earth’s climate. A new study of the St. Elias Range in coastal Alaska demonstrates how dynamic and coupled our planet’s crust is to climate, and how we can investigate past erosion through marine sediments.

Climate Transgressions and Barrier Islands

Barrier Islands support local economies, residents, tourism, fragile environments, and sometimes valuable resources. Yet, they are extremely susceptible to storms and sea level change. A new study examines the past 12,000 years in sediments to try to understand how these coastal landforms may be affected in the future.

The Great Barrier Reef is worth $15 billion – $20 billion AUS a year: A quick lesson in ecosystem economics

When discussing the value of an ecosystem, tensions run high. Some people evaluate ecosystems with heavy emphasis on non-use values, like aesthetics and spiritual appreciation. Other people value ecosystems based on things like natural resource availability and the potential for direct monetary revenue. It is difficult to assess the relative importance (or value) of these differing goals because the economic benefits of one are easily quantified while the other is more difficult to assess.

A volcano, a tropical cyclone, and a computer model walked into a room…

Like with bad jokes, timing is everything. The punch line doesn’t make sense if you don’t know the back story, just like when mixing active volcanoes, tropical cyclones, and new volcanic smog dispersion models.

The oldest seawater chemically analyzed

Water water everywhere, water water always there, but how it’s changed you may not know, read this story and Spear et al. will tell you so.

Need help counting bubbles? Now you can use sound!

Bubbles elicit scenes of childhood summers playing on the front stoop or backyard. On the other hand, put bubbles at the bottom of the ocean and you will find highly educated adults toiling with complicated mathematical equations and state-of-the-art technology.

Oceanography in space! Using a satellite to profile an extraterrestrial lake

In 2013, a satellite orbiting Saturn passed by its largest moon, Titan. The satellite track offered a rare opportunity to collect depth-sounding data of an extraterrestrial lake.

First evidence of deep explosive volcanic activity at the Marsili Seamount

The Marsili Seamount is the largest volcanic complex in the Mediterranean area and Europe. Previously thought to have last erupted between 100,000 and 1 million years ago, new evidence suggests the latest eruption was only 3 thousand years ago. Additionally, that eruption was explosive and deep (500-800 meters below sea level), resulting in several tephra deposits left for scientists to analyze.

Reconstructing climate history from sediments in the Gulf of Taranto, Italy

What was the climate like in Southern Italy 10,000 years ago? This question and many more can be answered by collecting sediment from the seafloor. Understanding the types of sediment and where it all came from, and determining the age of deposition make it possible to reconstruct the history of regional climate.

If Popocatépetl volcano blows, prepare for a few nights stuck in the airport.

Plinian eruptions have a high degree of material fragmentation, generating high altitude ash plumes that can travel far from the vent site. The impacts of these types of eruptions include hazards such as human health concerns, roof collapses, disruption of terrestrial communications, and the jeopardization of air travel.

Riding the Waves of Change: A Revised Beach Cycle for Mixed Sand and Gravel Beaches

A seasonal cycle of sand volume for typical sand beaches has been described for decades. This cycle does not hold true for beaches of mixed sand and gravel compositions. The highlighted study revises the beach cycle based off of observations during a year of strong storms. Improving our understanding of how the beach responds and recovers from powerful storms is the first step to protecting our vulnerable coastal communities.

From the beach to the abyss: A sand grain’s journey at La Réunion Island

The path a grain of sand takes from land to the deep sea is largely made possible by turbidity currents- dense currents of sediment and water traveling rapidly through the ocean. A recent study focused on La Réunion Island, a volcanic island in the Indian Ocean, highlights the importance of submarine canyons and turbidity currents in shaping the offshore geology.

Passing gas makes islanders feel a burn: CO2 degassing, low pH and the similarities between an underwater Greek volcano and two Cameroon lakes

Roughly 360 years ago, on a September afternoon in the Aegean sea, the sky was blotted out as metals tarnished and inhabitants complained of terrible eye pain. By the time the skies cleared on one island, roughly 70 people had died of asphyxiation. Today, the picturesque vacation destination is covered with blue roofed, white stucco buildings overlooking Aegean sunsets. What tourists can’t see from their hotel windows is the island’s neighbor, Kolumbo, an underwater volcano 7km to the northeast…

Catastrophic floods or drought? What caused the water level drop of glacial Lake Agassiz?

Formed from the meltwater of a colossal ice sheet that once blanketed North America, glacial Lake Agassiz experienced a sudden drop in water level approximately 12,900 years ago. The timing of this event aligns with a climatic return to cold conditions for 1,000 years, known as the Younger Dryas. A well-established hypothesis suggests that catastrophic drainage of Lake Agassiz explains the drop in water level and the associated abrupt climate change. This hypothesis has been recently challenged, explaining the drop in water level as a climate shift to desert-like conditions. How well does this competing hypothesis hold up?

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