Planetary
rumblings
In an extraordinary year of field research, our scientists pushed the frontier of knowledge about the geophysical mechanisms and mysteries hiding deep below the Earth's surface in order to better understand, and ultimately help mitigate, the risks of our ever-rumbling planet.
Terry Plank, Einat Lev and Nick Frearson are leading the world's first open-data, real-time, multi-sensor community experiment on active volcanoes. The AVERT project (Anticipating Volcanic Eruptions in Realtime) provides scientists with the infrastructure needed to predict a volcanic eruption hours to months before one occurs. This would be welcome news to the 800 million people around the world who live within 60 miles (ca. 100 kilometers) of an active volcano.
Frearson and his engineering group at Lamont hand-built low-power sensor systems with satellite uplinks and on-board computers that could remotely measure, analyze and transmit data on gas emissions, tiny earthquakes, and ground inflation. This information helps scientists pinpoint rising lava–all in real time. This summer, the team made the long journey to the eastern Aleutian Island of Umnak, Alaska, home to the Okmok caldera, one of the most explosively active volcanoes in the region. Working out of a ranch that was once a former WWII-era military base, the team shared a helicopter with scientists and engineers from the Alaska Volcano Observatory to set up their new instruments on the flanks of Okmok.
Reliable eruption forecasts have long eluded us, largely because scientists do not fully understand why magma starts or stops moving below the surface in the weeks, months, or years ahead of eruptions. Work by Dan Rasmussen and Plank shows that it is the magma’s water content that controls the depth at which the magma is stored under volcanoes like Okmok. The more water, the greater the depth. These findings are important because they connect magma depth to water content, and it is this water that fuels explosive eruptions. Their work also challenges the prevailing theory that magma stops rising when its density equals that of surrounding rock.
“I was always attracted to science and an academic career. Nobody in my family has done that, so there is no history. I applied for a PhD in Florence. I didn’t get in at first. I decided I’m going to get ready for next time to apply.” But a month later, his university advisor called him.
“My advisor said, ‘look, we have a project on snow. Are you interested?’ I said yes. And that was my key. I started to work on snow; I fell in love with the work. I went into the mountains and basically married this medium.”
Ultimately, he received his PhD in Italy from the Italian National Research Council in Florence, focusing on the interaction of electromagnetic waves and snow particles for satellite applications.
“My first day of PhD, my advisor came to me with three books totaling about 1000 pages and told me to come back to him once I had finished absorbing them. I only had a desk and a lamp, not even a computer.” Three months later, Tedesco went to his advisor, having finished the books and with a draft of a first paper.
In 2002, Tedesco began a research appointment at NASA Goddard Space Flight Center, left Avelino, and moved to Washington, D.C.
“I had one thousand dollars in my pocket, and my wife was pregnant with our first daughter,” said Tedesco. He also had a one-way hour and a half commute across the city each day. He used the time on the train and bus to read and study, learning to speak and write better English.
In 2008, Tedesco moved to the City College of New York (CCNY) as an Assistant Professor, where he was promoted to Associate Professor in 2012. At CCNY, he founded and directed the Cryosphere Processes Laboratory and
was a rotating program manager at the National Science Foundation between 2013 and 2015. In January 2016, Tedesco joined Lamont. Here, he continues researching the dynamics of seasonal snowpack and ice sheet surface properties and pursues fieldwork exploring exoplanetary biology on icy surfaces and global climate change and its implications on the economy, real estate, and socially vulnerable populations.
Much of Tedesco’s work and writings have focused on the remarkable decline of Arctic ice. During the summer of 2021, Tedesco and other climate scientists recorded daily melt rates seven times higher than usual.
A mid-August heatwave led to the first-ever recorded rainfall at Summit Camp, at the ice sheet's highest point. Seven billion tons of water fell on the ice sheet.
Tedesco called the rain event unique and alarming.
“Never in my life did I think I would see rain on Summit. It is called the dry snow zone of Greenland for a reason,” he said. “The imbalance of the Arctic system is screaming that there is substantial change going on characterized by multiple events rather than a single snapshot. It's consistent with what we were expecting to see based on models and our understanding of the physical processes. There is very little hope that things will be reversed because the processes we know are driving the acceleration of melting in Greenland and Antarctica have been there a while and cannot be easily stopped without drastic intervention on CO2 concentrations in the atmosphere.”
Tedesco observes the speed at which projected changes to polar ice are materializing with great concern.
“Changes are happening even faster than the most dire predictions are suggesting.”
Of particular concern, the injustice of climate change consequences. Too often, the communities that generate the least of the greenhouse gases that contribute to global warming are the people who suffer the most severe climate consequences.
During the summer of 2021, Tedesco and colleagues published The Socio-Economic Physical Housing Eviction Risk (SEPHER) dataset. It integrates socio-economic information with risk from wildfires, drought, coastal and riverine flooding, and other hazards, plus financial information from real estate databases and ethnicity, race, and gender data. The goal is to account for the economic vulnerability associated with the housing market that accounts for racial, gender, and ethnicity factors so that stakeholders can take appropriate action to protect vulnerable populations. SEPHER covers the entire United States, and Tedesco has made one of the pillars of this project that all data must be publicly accessible.
“The tool is aiming at quantifying objective analysis of the role of climate impacts in social and racial injustice, as in the case of climate gentrification and displacement or climate injustice.”
Tedesco will take his next expedition to Greenland in 2022 when he and Lamont paleoclimatologist Brendan Buckley go to a forest in southern Greenland to take tree ring samples to work on climate reconstruction of Greenland back to the 1800s.
“We want to know what happened before we were able to measure things,” he said. Since trees can live for hundreds—and sometimes even thousands—of years, a tree can experience various environmental conditions: wet years, dry years, cold years, hot years, early frosts, forest fires, and more. Tree rings can indicate how old the tree is and what the weather was like during each year of the tree's life. “The plan is to reach the only forest in Greenland, a patch of land longer no more than six miles, close to the place where Erik the Red arrived and named Greenland as we know it today. It is going to be an exciting trip!”
The pandemic forced a delay of this field study, which was slated for last year. The pandemic and its many restrictions also illuminated something for Tedesco, something disturbing, considering the kind of global collaboration required to cut greenhouse gas emissions and stave off some of the most catastrophic future climate consequences.
“As a species, we were not able to come together with masks and vaccines. If we can't come together with such a great and imminent threat [as COVID-19], how can we convince people that we need to take action for future generations? In this regard, the pandemic has given way to questions about the world around me.” However, Tedesco remains optimistic, especially when he thinks about the power of new generations, to adopt a lifestyle that considers economic and financial aspects and one sustainability and moral and ethical values.
In their quest to unlock the planet’s geologic secrets, Lamonters also took to the open seas. Cecilia McHugh, Leonardo Seeber, Michael Steckler and colleagues from other universities spent three weeks on the R/V Pelican coring and mapping the seafloor and sub-seafloor between Haiti and Jamaica. Their goal was to evaluate earthquake potential along the Enriquillo-Plantain Garden fault zone, which forms part of the northern boundary of the Caribbean and North American plates. Their expedition discovered stresses along the underwater plate boundary, as well as a rich record of past earthquakes, including the disastrous 1692 Port Royal and 1907 Kingston earthquakes. This new data will help scientists better understand the geohazard risks faced by the 15 million people who live in these two countries.
Relatedly, Anne Bécel, Tanner Acquisto, Brian Boston, and Brandon Shuck spent more than a month on the R/V Marcus G. Langseth off the west coast of Mexico, above where the young Cocos oceanic plate dives beneath the North American plate. They conducted the first-ever seismic imaging study of a portion of the subduction zone called the Guerrero seismic gap, which produces ‘slow earthquakes’ that release energy over many days or months. In contrast, most of the subduction zone has produced large earthquakes over the past 100 years, including the dramatic 8.0-magnitude Michoacán earthquake of 1985 that killed more than 10,000 people in Mexico City. The team's discoveries could unlock the secrets of slow earthquakes and the long-term hazards they pose to the people living nearby.
Continue reading to learn about the scientific discoveries we made at another dangerous fault…
A Slow-Motion Section of the San Andreas Fault May Not Be So Harmless After All
By Kevin Krajick
Most people know about the San Andreas Fault, the 800-mile-long seismic monster that cleaves California from south to north. Lesser known: the San Andreas is actually made up of three major sections that appear to move independently. The north segment was the source of the 1906 earthquake that leveled San Francisco; the southern one, the 1994 quake that hit near Los Angeles, collapsing a freeway and killing scores. The central segment, lying between the other two, is relatively harmless, with opposing tectonic plates slipping by each other at a steady, gentle pace without ever sticking together and building up stresses that can cause devastating jolts.
At least that is the story most scientists have been telling so far. But a study led by former Lamont graduate student Genevieve Coffey suggests that the central section, too, has hosted many major earthquakes that have gone unnoticed only because they occurred before written records.
The research team analyzed rocks from near the bottom of a 3.2-kilometer-deep borehole near the city of Parkfield, using a new method developed largely at Lamont. When earthquake faults slip, friction along the moving parts can cause temperatures to spike. This cooks the rocks, altering the makeup of organic compounds in sedimentary formations along the fault path. By calculating the degree of heating in these so-called biomarkers, geochemists can spot past events and roughly extrapolate the sizes of resulting earthquakes.
The researchers found many such altered compositions in a band of highly disturbed sedimentary rock lying between 3,192 and 3,196 meters (ca. 2 mi) below the surface. In all, they say the blackish, crumbly stuff showed signs of more than 100 quakes. In most, the fault appears to have jumped more than 1.5 meters (ca. 5 ft). This would translate to at least a magnitude 6.9 quake, the size of the deadly Northridge event. But many could well have been larger, as the method for estimating earthquake size is still evolving. Some could have been as big as the 1906 San Francisco disaster.
When did these quakes happen? Trenches dug across the central section have revealed no disturbed soil layers that would indicate quakes rupturing the surface in the last 2,000 years. But 2,000 years is an eye blink in geologic terms, and excavations could be missing any number of more recent quakes that did not rupture the surface.
To get at the timing, the researchers used a second new technique. Heated biomarkers run along narrow bands, from microscopic to just an inch or so wide. Other scientists have long used the ratio of radioactive potassium to argon to measure the ages of rocks; more argon means older rock. Conveniently for the authors, heating along faults drives out argon, resetting the radioactive “clock,” so that the heated rock appears younger than identical, unheated material nearby.
The rocks in question formed tens of millions of years ago in an ancient Pacific basin, but the rocks in the thin slip zones came out looking as young as 3.2 million years. This sets out only an upper limit, as the scientists still do not know how thoroughly the clock may have been reset; some quakes could have taken place just a few hundred or a few thousand years ago. The group is now working to refine the age interpretations.
“People should not be alarmed,” said Lamont geologist and study coauthor Stephen Cox. “Building codes in California are now quite good. Seismic events are inevitable. Work like this helps us figure out what is the biggest possible event, and helps everyone prepare.”
PLANETARY
RUMBLINGS
In an extraordinary year of field research, our scientists pushed the frontier of knowledge about the geophysical mechanisms and mysteries hiding deep below the Earth's surface in order to better understand, and ultimately help mitigate, the risks of our ever-rumbling planet.
Terry Plank, Einat Lev and Nick Frearson are leading the world's first open-data, real-time, multi-sensor community experiment on active volcanoes. The AVERT project (Anticipating Volcanic Eruptions in Realtime) provides scientists with the infrastructure needed to predict a volcanic eruption hours to months before one occurs. This would be welcome news to the 800 million people around the world who live within 60 miles (ca. 100 kilometers) of an active volcano.
Frearson and his engineering group at Lamont hand-built low-power sensor systems with satellite uplinks and on-board computers that could remotely measure, analyze and transmit data on gas emissions, tiny earthquakes, and ground inflation. This information helps scientists pinpoint rising lava–all in real time. This summer, the team made the long journey to the eastern Aleutian Island of Umnak, Alaska, home to the Okmok caldera, one of the most explosively active volcanoes in the region. Working out of a ranch that was once a former WWII-era military base, the team shared a helicopter with scientists and engineers from the Alaska Volcano Observatory to set up their new instruments on the flanks of Okmok.
Reliable eruption forecasts have long eluded us, largely because scientists do not fully understand why magma starts or stops moving below the surface in the weeks, months, or years ahead of eruptions. Work by Dan Rasmussen and Plank shows that it is the magma’s water content that controls the depth at which the magma is stored under volcanoes like Okmok. The more water, the greater the depth. These findings are important because they connect magma depth to water content, and it is this water that fuels explosive eruptions. Their work also challenges the prevailing theory that magma stops rising when its density equals that of surrounding rock.
In their quest to unlock the planet’s geologic secrets, Lamonters also took to the open seas. Cecilia McHugh, Leonardo Seeber, Michael Steckler and colleagues from other universities spent three weeks on the R/V Pelican coring and mapping the seafloor and sub-seafloor between Haiti and Jamaica. Their goal was to evaluate earthquake potential along the Enriquillo-Plantain Garden fault zone, which forms part of the northern boundary of the Caribbean and North American plates. Their expedition discovered stresses along the underwater plate boundary, as well as a rich record of past earthquakes, including the disastrous 1692 Port Royal and 1907 Kingston earthquakes. This new data will help scientists better understand the geohazard risks faced by the 15 million people who live in these two countries.
Relatedly, Anne Bécel, Tanner Acquisto, Brian Boston, and Brandon Shuck spent more than a month on the R/V Marcus G. Langseth off the west coast of Mexico, above where the young Cocos oceanic plate dives beneath the North American plate. They conducted the first-ever seismic imaging study of a portion of the subduction zone called the Guerrero seismic gap, which produces ‘slow earthquakes’ that release energy over many days or months. In contrast, most of the subduction zone has produced large earthquakes over the past 100 years, including the dramatic 8.0-magnitude Michoacán earthquake of 1985 that killed more than 10,000 people in Mexico City. The team's discoveries could unlock the secrets of slow earthquakes and the long-term hazards they pose to the people living nearby.
Continue reading to learn about the scientific discoveries we made at another dangerous fault…
A Slow-Motion Section of the San Andreas Fault May Not Be So Harmless After All
By Kevin Krajick
Most people know about the San Andreas Fault, the 800-mile-long seismic monster that cleaves California from south to north. Lesser known: the San Andreas is actually made up of three major sections that appear to move independently. The north segment was the source of the 1906 earthquake that leveled San Francisco; the southern one, the 1994 quake that hit near Los Angeles, collapsing a freeway and killing scores. The central segment, lying between the other two, is relatively harmless, with opposing tectonic plates slipping by each other at a steady, gentle pace without ever sticking together and building up stresses that can cause devastating jolts.
At least that is the story most scientists have been telling so far. But a study led by former Lamont graduate student Genevieve Coffey suggests that the central section, too, has hosted many major earthquakes that have gone unnoticed only because they occurred before written records.
The research team analyzed rocks from near the bottom of a 3.2-kilometer-deep borehole near the city of Parkfield, using a new method developed largely at Lamont. When earthquake faults slip, friction along the moving parts can cause temperatures to spike. This cooks the rocks, altering the makeup of organic compounds in sedimentary formations along the fault path. By calculating the degree of heating in these so-called biomarkers, geochemists can spot past events and roughly extrapolate the sizes of resulting earthquakes.
The researchers found many such altered compositions in a band of highly disturbed sedimentary rock lying between 3,192 and 3,196 meters (ca. 2 mi) below the surface. In all, they say the blackish, crumbly stuff showed signs of more than 100 quakes. In most, the fault appears to have jumped more than 1.5 meters (ca. 5 ft). This would translate to at least a magnitude 6.9 quake, the size of the deadly Northridge event. But many could well have been larger, as the method for estimating earthquake size is still evolving. Some could have been as big as the 1906 San Francisco disaster.
When did these quakes happen? Trenches dug across the central section have revealed no disturbed soil layers that would indicate quakes rupturing the surface in the last 2,000 years. But 2,000 years is an eye blink in geologic terms, and excavations could be missing any number of more recent quakes that did not rupture the surface.
To get at the timing, the researchers used a second new technique. Heated biomarkers run along narrow bands, from microscopic to just an inch or so wide. Other scientists have long used the ratio of radioactive potassium to argon to measure the ages of rocks; more argon means older rock. Conveniently for the authors, heating along faults drives out argon, resetting the radioactive “clock,” so that the heated rock appears younger than identical, unheated material nearby.
The rocks in question formed tens of millions of years ago in an ancient Pacific basin, but the rocks in the thin slip zones came out looking as young as 3.2 million years. This sets out only an upper limit, as the scientists still do not know how thoroughly the clock may have been reset; some quakes could have taken place just a few hundred or a few thousand years ago. The group is now working to refine the age interpretations.
“People should not be alarmed,” said Lamont geologist and study coauthor Stephen Cox. “Building codes in California are now quite good. Seismic events are inevitable. Work like this helps us figure out what is the biggest possible event, and helps everyone prepare.”
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Editors: Francesco Fiondella, Marian Mellin, Stacey Vassallo I Contributing Writers: Kevin Krajick, Sarah Fecht, Marie DeNoia Aronsohn I Design: Carmen Neal
Columbia Climate School Lamont-Doherty Earth Observatory Annual Report FY2022
© 2022 by The Trustees of Columbia University in the City of New York, Lamont-Doherty Earth Observatory. All rights reserved.
Editors: Francesco Fiondella, Marian Mellin, Stacey Vassallo I Contributing Writers: Kevin Krajick, Sarah Fecht, Marie DeNoia Aronsohn I Design: Carmen Neal
Columbia Climate School Lamont-Doherty Earth Observatory Annual Report FY2022
© 2022 by The Trustees of Columbia University in the City of New York, Lamont-Doherty Earth Observatory. All rights reserved.