Kīlauea’s Summit Collapsed Into Itself

By Erik Klemetti | October 17, 2018 8:50 am
The new shape of Kīlauea's summit area, where the caldera floor collapsed over the course of the summer. USGS/HVO.

The new shape of Kīlauea’s summit area, where the caldera floor collapsed over the course of the summer. USGS/HVO.

A few weeks back I wrote about how much the lower East Rift Zone of Hawaii’s Kīlauea had been changed by this summer’s eruption. Over half a cubic kilometer of lava came pouring out of the multitude of fissures that opening in Leilani Estates and the neighboring area and 850 acres were added to the Big Island from all those lava flows entering the ocean. It was one of the largest eruptions in the last few centuries at the giant volcano. Yet, the LERZ eruption might not have been the most dramatic change that happened at Kīlauea. To see that, we need to look at what happened at the top.

First, a little background on shield volcanoes like Kīlauea. They are huge edifices and at Hawaii, they rise from the seafloor to a summit that might be hundreds to thousands of meters above sea level. One common feature at the summit of these volcanoes are calderas, which are depressions that are caused by collapses of the land’s surface. Unlike volcanoes such as the ones found in the Andes or Japan, these calderas don’t need to be formed by a massive, explosive eruption — think Crater Lake in Oregon — but rather a gradual collapse. Some of the calderas on Kīlauea were formed by more explosive events, but many weren’t. Barðarbunga the volcano in Iceland that fed the Holuhraun lava field during 2014-15 also experienced one of these gradual caldera collapses, albeit one that was under a sheet of ice.

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Earthquakes, Tsunamis and Eruptions in Indonesia

By Erik Klemetti | October 3, 2018 8:38 am
Landsat 8 image showing the damage to Palu from the M7.5 earthquake and tsunami. NASA Earth Observatory.

Landsat 8 image showing the damage to Palu from the M7.5 earthquake and tsunami. NASA Earth Observatory.

The earthquake and tsunami that happened last week on Sulawesi in Indonesia has been more devastating than anyone expected. The number of deaths in and around Palu has topped 1,400 and aid has been slow to reach the survivors due to the damage to infrastructure in the area. It is still unclear exactly what triggered the tsunami that followed the M7.5 earthquake — there is speculation it was an undersea landslide that followed the temblor. What is known is that this earthquake ruptured a long stretch of the island with displacement of over 5 meters along the strike-slip (side by side) fault (see below). We also know that Indonesia’s early warning system for tsunamis, built mainly after the 2004 Boxing Day tsunami, did not appear to operate as planned.

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Violent Tsunami Strikes Palu in Indonesia

By Erik Klemetti | September 28, 2018 8:30 am
Map showing the epicenter and expected shaking related to a M7.5 earthquake near Palu in Indonesia. USGS.

Map showing the epicenter and expected shaking related to a M7.5 earthquake near Palu in Indonesia. USGS.

A M7.5 earthquake struck on the Indonesian island of Sulawesi today and it appears to have generated a significant tsunami that struck, at the very least, the city of Palu. The city is only about 78 kilometers from the epicenter of the earthquake. This uncorroborated video on Twitter shows the wave arriving:

Here is another video from Instagram. The Associated Press is reporting that the PVMBG in Indonesia has confirmed a tsunami struck and was caught on video, while Indonesia’s emergency management agency (BMKG) issued a warning about a tsunami from this earthquake.

UPDATE 9/29: The news out of Palu is grim. The tsunami was ~3 meters (10 feet) and the combined impact of the waves and the earthquake has killed at least 380 people. It does appear that Indonesian scientists think it was indeed a submarine landslide (see below) that caused the tsunami while other landslides on the island have cut off transportation routes. Apparently there was to be a beach festival that evening in Palu, so more people than usual may have been on the beaches. Images from the area show significant damage caused by the earthquake as well:

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The Impact of the 2018 Kīlauea Eruption

By Erik Klemetti | September 26, 2018 12:44 pm
The now-quiet Fissure 8 cone on Kīlauea's lower East Rift Zone. USGS/HVO.

The now-quiet Fissure 8 cone on Kīlauea’s lower East Rift Zone. USGS/HVO.

It has been quiet at Kīlauea in Hawaii. The eruption on the lower East Rift Zone that captured the planet’s attention over the summer trickled to a stop in late August and since then there hasn’t been much going on at all at the giant shield volcano. In fact, the Hawaii Volcano Observatory reports that carbon dioxide emissions at Kīlauea are lower than anything they’ve seen in over a decade. Earthquakes and collapses are now infrequent on the volcano and nary a lava flow can be seen at the surface, even deep in the Fissure 8 cinder cone built on the site of Leilani Estates. Even the ubiquitous deformation that was happening at the summit (deflation) and in the lower East Rift Zone (inflation) have vanished. Hawaii Volcanoes National Park reopened to tourists this past week after closing the whole summit of Kīlauea. By no means is anyone declaring the eruption over, but right now, Kīlauea really not doing much.

So, let’s take stock in what happened during the eruption. Here’s some of the data: approximately 35.5 square kilometers of the big island were repaved with lava, which includes ~3.5 square kilometers added to the island. That’s roughly twice the size of Key West in Florida but only 0.3% of the area of the island of Hawaii itself.

A rough estimate of the total volume erupted is 0.5 cubic kilometers, putting it at about half the size of the 2014-15 Holuhraun eruption in Iceland but amongst the largest in recorded history from Kīlauea (which is the last ~250 years). However, that is still enough to coat the entire island of Manhattan with ~8.5 meters (~27 feet) of lava. Although the number is still not certain, likely over 700 homes were destroyed along with other structures across the area from Leilani Estates to Vacationland Hawaii, where the lava filled in Kapoho Bay entirely.

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The Palmdale Bulge: A Geo-Crisis That Likely Never Existed

By Erik Klemetti | September 19, 2018 1:12 pm
September 2006 MODIS image of southern California taken by the Aqua satellite. NASA Earth Observatory.

September 2006 MODIS image of southern California taken by the Aqua satellite. NASA Earth Observatory.

The revolution in how we survey and image the surface of the Earth has had profound impacts on the geosciences. This shouldn’t be a shock to anyone as that’s what geoscientists do — study the Earth — and as we get more and better data on the planet and its surface, the better our understanding will become (and the more questions we can ask). Few technological leaps have been more important to geosciences than satellite imaging of the Earth.

That is more than just taking cool pictures of the planet, but also collecting location and elevation data of the surface … and being able to do so in sub-centimeter precision and repeatedly over intervals of days (or less). Combine that with land-based tools like LIDAR (Light Detection and Ranging), and suddenly we can notice very small changes in the Earth’s surface. Dump all this data in a geographic information system (GIS) and we can really start picking apart almost every up and down and slide and whatever comes along. Add high-powering computing to model the physical processes and the geosciences of 2018 would look like straight up science fiction to a geologist from 1975.

Oh, but as that implies, it wasn’t always so good. Before this level of precision and accuracy in mapping the Earth’s surface, geoscientists had to rely on tools like optical leveling, tilt-meters and other more analog methods for seeing how the Earth’s surface might be changing. This is not to say that amazing maps weren’t made, but they took a lot of time and people-power to construct … and was we’ve found, they weren’t always right.

That gets us to the Palmdale Bulge.

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What is the Evidence for Hurricanes in the Distant Past?

By Erik Klemetti | September 12, 2018 9:04 am
Aqua MODIS image of Hurricane Florence, seen on September 11, 2018. NASA.

Aqua MODIS image of Hurricane Florence, seen on September 11, 2018. NASA.

Hurricanes are massive meteorological events and, as we’ve seen recently in Puerto Rico, enormous humanitarian disasters. Yet, on a geologic timescale, massive storms like hurricanes and typhoons are ephemeral moments that are surprisingly difficult to read in the rock record, even if they seem like such powerful forces when they occur. Right now, Hurricane Florence is bearing down on the  Carolinas and it makes me wonder, what evidence could we expect to find for the hurricane 100, 1,000 or 10,000 years in the future?

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Five Things All College Students Should Know About the Earth

By Erik Klemetti | August 28, 2018 2:13 pm
The Horn of Africa seen from the International Space Station in January 2015, taken by ESA astronaut Samantha Cristoforetti. NASA.

The Horn of Africa seen from the International Space Station in January 2015, taken by ESA astronaut Samantha Cristoforetti. NASA.

So, another school year starts Thursday (for me) and I thought I’d offer a list of 5 things all college students should know about the Earth, whether they take a geology classes or not (but you really should take at least one).

#1 The Earth is 4.54 billion years old (give or take a few million years)

This is “long history”. About 4.54 billion years ago, the Earth was formed out of the pile of debris and gases that surrounded our just-born Sun. How do we know this? By determining the age of meteorites that match the composition of the early solar system using the isotopes produced by radioactive decay. We can find some evidence of the first minerals produced in the early Earth by dating zircon at the Jack Hills in Australia, and they reach back to about 4.4 billion years ago. Modern Homo sapiens have only been around for a whopping 0.004% of the history of our planet.

#2 Rocks record the evidence of evolution of life on Earth

Speaking of when Homo sapiens arrived on the scene, the rocks of Earth contain all the evidence for evolution as the driving mechanism for the diversity of life on Earth. Since life appeared ~3.8 billion years ago, rocks have been capturing a long (and somewhat incomplete) record of organisms that existed on land and in the seas. It is this “long history” that is needed to really appreciate how life has changed to meet the demands of a changing planet.

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CATEGORIZED UNDER: Rocky Planet, Science, Science Blogs

Venezuela Rocked By Large Earthquake

By Erik Klemetti | August 21, 2018 7:01 pm
Map of shaking felt by the M7.3 earthquake in Venezuela on August 21, 2018. USGS.

Map of shaking felt by the M7.3 earthquake in Venezuela on August 21, 2018. USGS.

Venezuela was hit by a M7.3 earthquake today, causing extensive damage across the northern part of the country as well as nearby Trinidad & Tobago. Shaking was felt as far away at Bogotá, Martinique and Guyana, thousands of kilometers from the earthquake’s epicenter. This temblor may have been the largest earthquake to strike Venezuela since a M7.7 hit off of Caracas in 1900.

Video and images of the earthquake have quickly found their way to Twitter, so here are some examples (special thanks to Austin Elliot for some of these links):

The depth of the earthquake meant the shaking was felt widely across the region and from the looks of it, there was some sustained shaking but that depth might also mean that massive destruction was avoided. Some reports suggest that only minor to moderate damage was seen (see below) in cities relatively close to the epicenter. No injuries have been reported so far, however, news is slow to come out of the country due to its current political crisis

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Wilderness vs. Monitoring: The Controversy of a New Seismic Network at Glacier Peak

By Erik Klemetti | August 19, 2018 3:34 pm
Glacier Peak in Washington. Wikimedia Commons.

Glacier Peak in Washington. Wikimedia Commons.

One of the most potentially dangerous volcanoes in the Cascades is Glacier Peak in Washington. It produced the one of the largest eruptions in the past 20,000 years in this volcanic range that spans from British Columbia to California. Multiple eruptions around 13,500 years ago spread ash all the way into Montana. Over the last 2,000 years, there have been multiple explosive eruptions that have impacted what became Washington state and beyond. Put on top of that the many glaciers on the slopes of Glacier Peak that could help form volcanic mudflows (lahars) during a new eruption, and you can see that Glacier Peak is a real threat.

Yet, even with this hazard posed by the volcano, there is very little in the way of monitoring equipment on the volcano. Currently, there is a lone seismometer on Glacier Peak to measure earthquakes, one of the most important pieces of information needed to monitor volcanoes. A single seismometer is better than no seismometer, but it can only give us so much information. Without a network of at least 3 seismometers (a“seismic network”), we can really only measure if earthquakes are occurring at the volcano and not exactly where and how far beneath the volcano the temblors are happening. This is what is installed at a truly restless volcano like Mount St. Helens.

These two pieces of information — location and depth — are vital for understanding what might be happening at Glacier Peak if any earthquake swarm were to happen. Otherwise, we might have difficulty differentiating between earthquakes happening due to fault motion near the volcano or shallow changes in the hydrothermal system in the volcano rather than magma moving into the volcano from deep below.

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Is the Kīlauea Eruption Winding Down?

By Erik Klemetti | August 14, 2018 9:54 am
The steaming cone at Fissure 8 with some small pockets of molten lava in the main vent area. Taken August 12, 2018. USGS/HVO.

The steaming cone at Fissure 8 with some small pockets of molten lava in the main vent area. Taken August 12, 2018. USGS/HVO.

It has been awhile since I updated on the lower East Rift Zone eruption on Hawaii’s Kīlauea. Well, it appears that the eruption is slowing down significantly. The fountaining at the Fissure 8 cone has stopped (see above) and the lava lake that formed there has gotten sluggish and sticky. Does this mean we’re seeing the end of the eruption that has paved over so many homes and added to the Big Island? That is hard to say with any certainty at this point.

There are still dribbles of lava making it to the ocean entry between the Kapoho Bay and Ahalanui, meaning that there is still some lava being fed into the lava tube system that has formed, all being fed by Fissure 8. However, that might be merely lava making its way through the system, so the USGS is watching closely to see if the ocean entries end altogether with this waning activity.

The earthquakes and collapses at the summit seem to have slowed down sharply as well. A month ago, the summit was seeing dozens of small to moderate earthquakes each day, but now only 3 earthquakes struck on the summit on August 13. Combine that with the lowest sulfur dioxide emissions measured on Kīlauea in a decade, and all in all, it seems that something has changed over the last week.

Now, it would be easy to say that the eruption is ending, but it might not be that simple. The lack of vigorous eruptions, the low sulfur dioxide, the settling of the summit earthquakes, they all point to the idea that there is less magma moving in the system underneath Kīlaeau at this moment. However, when you look at eruptions like this that have happened around the world, they can wax and wane, so this brief pause might be just that: a pause. It will take likely months of these conditions before the Hawaii Volcano Observatory would declare this eruption as “over”.

CATEGORIZED UNDER: Rocky Planet, Science, Science Blogs
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Rocky Planet

Rocky Planet covers all the geologic events that made and will continue to shape our planet. From volcanoes to earthquakes to gold to oceans to other solar systems, I discuss what is intriguing and illuminating about the rocks beneath our feet and above our heads. Ever wonder what volcanoes are erupting? How tsunamis form and where? What rocks can tell us about ancient environments? How the Earth might change in the future? You'll find these answers and more on Rocky Planet.
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