Cascadian Megaquake Resilience - Revision history

TH: /* Bridge Failures */

2023-08-14T22:45:48Z

Bridge Failures

← Older revision		Revision as of 22:45, 14 August 2023
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	As reported by NBC (KGW) in 2016, most of Portland's bridges cannot withstand the coming megaquake as they are old and were never designed to withstand earthquakes. According to Bruce Johnson, state bridge engineer for the Oregon Department of Transportation, a lot of these bridges will be unusable for months after the quake. The least prepared of these is the Interstate Bridge, which carries over 130,000 cars and trucks over the [[Wimahl River]] ("Columbia") every day and would likely collapse under a 9.0 megaquake.		As reported by NBC (KGW) in 2016, most of Portland's bridges cannot withstand the coming megaquake as they are old and were never designed to withstand earthquakes. According to Bruce Johnson, state bridge engineer for the Oregon Department of Transportation, a lot of these bridges will be unusable for months after the quake. The least prepared of these is the Interstate Bridge, which carries over 130,000 cars and trucks over the [[Wimahl River]] ("Columbia") every day and would likely collapse under a 9.0 megaquake.

	Government records indicate that the Ross Island, Hawthorne, Steel and Broadway Bridges would likely collapse, the Morrison and Burnside bridges might remain standing with extensive damage, and the approaches to the Marquam and Freemont bridges would collapse.<ref>https://web.archive.org/web/20180212025605/http://www.kgw.com/article/news/investigations/the-portland-bridges-that-will-collapse-in-an-earthquake/283-291062061</ref>		Government records indicate that the Ross Island, Hawthorne, Steel and Broadway Bridges would likely collapse, the Morrison and Burnside bridges might remain standing with extensive damage, and the approaches to the Marquam and Freemont bridges would collapse.<ref>https://web.archive.org/web/20180212025605/http://www.kgw.com/article/news/investigations/the-portland-bridges-that-will-collapse-in-an-earthquake/283-291062061</ref> Only one bridge in the city is currently up to seismic standards, the Sellwood bridge.<ref>https://www.wweek.com/news/city/2019/03/06/four-rumors-have-sprouted-during-portlands-earthquake-backlash-whats-the-truth/</ref>

	Six years later in 2022, Multnomah County's EIS Report re-affirmed that:		Six years later in 2022, Multnomah County's EIS Report re-affirmed that:

TH: /* Bridge Failures */

2023-08-14T22:39:35Z

Bridge Failures

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	==== Bridge Failures ====		==== Bridge Failures ====

	Multnomah County EIS Report~~, 4/22/2022~~:		As reported by NBC (KGW) in 2016, most of Portland's bridges cannot withstand the coming megaquake as they are old and were never designed to withstand earthquakes. According to Bruce Johnson, state bridge engineer for the Oregon Department of Transportation, a lot of these bridges will be unusable for months after the quake. The least prepared of these is the Interstate Bridge, which carries over 130,000 cars and trucks over the [[Wimahl River]] ("Columbia") every day and would likely collapse under a 9.0 megaquake.

			Government records indicate that the Ross Island, Hawthorne, Steel and Broadway Bridges would likely collapse, the Morrison and Burnside bridges might remain standing with extensive damage, and the approaches to the Marquam and Freemont bridges would collapse.<ref>https://web.archive.org/web/20180212025605/http://www.kgw.com/article/news/investigations/the-portland-bridges-that-will-collapse-in-an-earthquake/283-291062061</ref>

			Six years later in 2022, Multnomah County's EIS Report re-affirmed that:

	<blockquote>"Absent significant and targeted infrastructure resiliency improvements, the next CSZ earthquake is expected to render all of the downtown Portland Willamette River crossings unusable (either because of damage to each crossing’s bridge, its approaches, or both). This means that none of the designated lifeline routes or evacuation routes across the river will be available for emergency response, rescue, or evacuation immediately following the earthquake."<ref>https://wppo.blob.core.windows.net/ooh-burnside-eis-22/2022/04/SDEIS-Chapter-1-Purpose-and-Need-for-the-Project-1.pdf</ref></blockquote>		<blockquote>"Absent significant and targeted infrastructure resiliency improvements, the next CSZ earthquake is expected to render all of the downtown Portland Willamette River crossings unusable (either because of damage to each crossing’s bridge, its approaches, or both). This means that none of the designated lifeline routes or evacuation routes across the river will be available for emergency response, rescue, or evacuation immediately following the earthquake."<ref>https://wppo.blob.core.windows.net/ooh-burnside-eis-22/2022/04/SDEIS-Chapter-1-Purpose-and-Need-for-the-Project-1.pdf</ref></blockquote>

TH: /* Bridge Failures */

2023-08-14T18:07:54Z

Bridge Failures

← Older revision		Revision as of 18:07, 14 August 2023
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	[https://www.multco.us/earthquake-ready-burnside-bridge/supplemental-draft-environmental-impact-statement Full Environmental Impact Statement]		[https://www.multco.us/earthquake-ready-burnside-bridge/supplemental-draft-environmental-impact-statement Full Environmental Impact Statement]

	~~Projected~~ Simulation of [https://www.youtube.com/watch?v=sn98JkN5HXc Burnside Bridge Collapse]		Simulation of [https://www.youtube.com/watch?v=sn98JkN5HXc Burnside Bridge Collapse]

			Burnside Bridge Resilience Project [https://www.multco.us/earthquake-ready-burnside-bridge Official Website]

	=== Vancouver ===		=== Vancouver ===

TH: /* Bridge Failures */

2023-08-11T17:18:39Z

Bridge Failures

← Older revision		Revision as of 17:18, 11 August 2023
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	[https://www.multco.us/earthquake-ready-burnside-bridge/supplemental-draft-environmental-impact-statement Full Environmental Impact Statement]		[https://www.multco.us/earthquake-ready-burnside-bridge/supplemental-draft-environmental-impact-statement Full Environmental Impact Statement]

			Projected Simulation of [https://www.youtube.com/watch?v=sn98JkN5HXc Burnside Bridge Collapse]

	=== Vancouver ===		=== Vancouver ===

TH at 21:01, 10 August 2023

2023-08-10T21:01:04Z

← Older revision		Revision as of 21:01, 10 August 2023
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	One of the advances in the most recent report, compared to previous studies, is the ability of researchers to detect which areas are prone to liquefaction, wherein saturated soil behaves more like a liquid than a solid. Vast swaths of Portland's west side, a large stretch of the south bank of the Columbia River and portions of the city's inner east side are all at high risk of liquefaction or landslides, especially if the quake strikes during the wet winter months, the report said.		One of the advances in the most recent report, compared to previous studies, is the ability of researchers to detect which areas are prone to liquefaction, wherein saturated soil behaves more like a liquid than a solid. Vast swaths of Portland's west side, a large stretch of the south bank of the Columbia River and portions of the city's inner east side are all at high risk of liquefaction or landslides, especially if the quake strikes during the wet winter months, the report said.

			==== Mega Oil Spill ====

			A joint City of Portland/Multnomah County report issued in 2021 warned that "this quake could trigger one of the largest oil spills in history that would destroy the Willamette River’s ecology and nearby residential areas."

			The Portland Bureau of Emergency Management concurred that in the megaquake, the [[Portland Terminal]] operated by [[Zenith Energy]] "and all the tank farms there pose a really grave threat to the city, the county, the region, the whole state, and environment in an earthquake," which “we've known for a long time."<ref>https://www.portlandmercury.com/news/2021/07/26/35406357/industrial-hub-in-northwest-portland-will-cause-catastrophic-oil-spill-during-earthquake-report-finds</ref>

	==== Bridge Failures ====		==== Bridge Failures ====

TH: /* 2015 FEMA PROJECTION */

2023-08-10T20:36:35Z

2015 FEMA PROJECTION

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	Some of the major cities along the length of the Cascade Volcanic Arc include Portland, Seattle, and Vancouver, and the population in the region exceeds 10 million. All could be potentially affected by volcanic activity and great subduction-zone earthquakes along the arc.<ref>https://en.wikipedia.org/wiki/Cascade_Volcanoes</ref>		Some of the major cities along the length of the Cascade Volcanic Arc include Portland, Seattle, and Vancouver, and the population in the region exceeds 10 million. All could be potentially affected by volcanic activity and great subduction-zone earthquakes along the arc.<ref>https://en.wikipedia.org/wiki/Cascade_Volcanoes</ref>

	== 2015 FEMA ~~PROJECTION~~ ==		== 2015 FEMA Projection ==

	<blockquote>The more catastrophic scenario is for a 9.0 earthquake along the entire zone from Canada to the California border. That would destroy much of the infrastructure west of the Cascades, according to state and federal officials.		<blockquote>The more catastrophic scenario is for a 9.0 earthquake along the entire zone from Canada to the California border. That would destroy much of the infrastructure west of the Cascades, according to state and federal officials.

TH: /* Worst-Case Scenario */

2023-08-10T20:36:16Z

Worst-Case Scenario

← Older revision		Revision as of 20:36, 10 August 2023
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	Some of the major cities along the length of the Cascade Volcanic Arc include Portland, Seattle, and Vancouver, and the population in the region exceeds 10 million. All could be potentially affected by volcanic activity and great subduction-zone earthquakes along the arc.<ref>https://en.wikipedia.org/wiki/Cascade_Volcanoes</ref>		Some of the major cities along the length of the Cascade Volcanic Arc include Portland, Seattle, and Vancouver, and the population in the region exceeds 10 million. All could be potentially affected by volcanic activity and great subduction-zone earthquakes along the arc.<ref>https://en.wikipedia.org/wiki/Cascade_Volcanoes</ref>

	== ~~Worst-Case Scenario~~ ==		== 2015 FEMA PROJECTION ==

	<blockquote>The more catastrophic scenario is for a 9.0 earthquake along the entire zone from Canada to the California border. That would destroy much of the infrastructure west of the Cascades, according to state and federal officials.		<blockquote>The more catastrophic scenario is for a 9.0 earthquake along the entire zone from Canada to the California border. That would destroy much of the infrastructure west of the Cascades, according to state and federal officials.

TH: /* Portland */

2023-08-10T20:34:12Z

Portland

← Older revision		Revision as of 20:34, 10 August 2023
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	One of the advances in the most recent report, compared to previous studies, is the ability of researchers to detect which areas are prone to liquefaction, wherein saturated soil behaves more like a liquid than a solid. Vast swaths of Portland's west side, a large stretch of the south bank of the Columbia River and portions of the city's inner east side are all at high risk of liquefaction or landslides, especially if the quake strikes during the wet winter months, the report said.		One of the advances in the most recent report, compared to previous studies, is the ability of researchers to detect which areas are prone to liquefaction, wherein saturated soil behaves more like a liquid than a solid. Vast swaths of Portland's west side, a large stretch of the south bank of the Columbia River and portions of the city's inner east side are all at high risk of liquefaction or landslides, especially if the quake strikes during the wet winter months, the report said.

			==== Bridge Failures ====

			Multnomah County EIS Report, 4/22/2022:

			<blockquote>"Absent significant and targeted infrastructure resiliency improvements, the next CSZ earthquake is expected to render all of the downtown Portland Willamette River crossings unusable (either because of damage to each crossing’s bridge, its approaches, or both). This means that none of the designated lifeline routes or evacuation routes across the river will be available for emergency response, rescue, or evacuation immediately following the earthquake."<ref>https://wppo.blob.core.windows.net/ooh-burnside-eis-22/2022/04/SDEIS-Chapter-1-Purpose-and-Need-for-the-Project-1.pdf</ref></blockquote>

			[https://www.multco.us/earthquake-ready-burnside-bridge/supplemental-draft-environmental-impact-statement Full Environmental Impact Statement]

	=== Vancouver ===		=== Vancouver ===

TH: /* Volcanic Eruptions */

2023-08-10T01:42:14Z

Volcanic Eruptions

← Older revision		Revision as of 01:42, 10 August 2023
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	<blockquote>"Explosively erupting volcanoes and megathrust earthquakes (Mw 8+ magnitude) occur at subduction zones. At many locations and times volcanic eruptions occur just before or after megathrust earthquakes. Examples globally include the eruption of Cordon Caulle volcano following the 1960 Chilean Mw 9.0+ earthquake; the 1707 eruption of Mount Fuji after the Mw 8.6 Nankai megathrust earthquake; the 2004 Mw 9.1+ Sumatra-Andaman megathrust earthquake followed by the 2005 eruptions of Talang, Egon and Barren Island volcanoes. Timing linkages between megathrust earthquakes and volcanic eruptions might be found in Kamchatka, Alaska, and Central America.		<blockquote>"Explosively erupting volcanoes and megathrust earthquakes (Mw 8+ magnitude) occur at subduction zones. At many locations and times volcanic eruptions occur just before or after megathrust earthquakes. Examples globally include the eruption of Cordon Caulle volcano following the 1960 Chilean Mw 9.0+ earthquake; the 1707 eruption of Mount Fuji after the Mw 8.6 Nankai megathrust earthquake; the 2004 Mw 9.1+ Sumatra-Andaman megathrust earthquake followed by the 2005 eruptions of Talang, Egon and Barren Island volcanoes. Timing linkages between megathrust earthquakes and volcanic eruptions might be found in Kamchatka, Alaska, and Central America.

	Some work has been conducted to explore possible triggering relationships in subduction systems, but the Cascadia Subduction Zone in the U.S. Pacific Northwest is missing this perspective."		Some work has been conducted to explore possible triggering relationships in subduction systems, but the Cascadia Subduction Zone in the U.S. Pacific Northwest is missing this perspective."</blockquote>

	= Emergency Preparedness =		= Emergency Preparedness =

TH: /* Volcanic Eruptions */

2023-08-10T01:42:01Z

Volcanic Eruptions

← Older revision		Revision as of 01:42, 10 August 2023
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	== Volcanic Eruptions ==		== Volcanic Eruptions ==

	The Cascade Mountains are volcanically active		The Cascade Mountains are volcanically active and it is possible the next megaquake will trigger a volcanic eruption.

	https://ui.adsabs.harvard.edu/abs/2018AGUFM.T13H0317G/abstract		As reported by the American Geophysical Union in its Fall 2018 Meeting<ref>https://ui.adsabs.harvard.edu/abs/2018AGUFM.T13H0317G/abstract</ref>:

			<blockquote>"Explosively erupting volcanoes and megathrust earthquakes (Mw 8+ magnitude) occur at subduction zones. At many locations and times volcanic eruptions occur just before or after megathrust earthquakes. Examples globally include the eruption of Cordon Caulle volcano following the 1960 Chilean Mw 9.0+ earthquake; the 1707 eruption of Mount Fuji after the Mw 8.6 Nankai megathrust earthquake; the 2004 Mw 9.1+ Sumatra-Andaman megathrust earthquake followed by the 2005 eruptions of Talang, Egon and Barren Island volcanoes. Timing linkages between megathrust earthquakes and volcanic eruptions might be found in Kamchatka, Alaska, and Central America.

			Some work has been conducted to explore possible triggering relationships in subduction systems, but the Cascadia Subduction Zone in the U.S. Pacific Northwest is missing this perspective."

	= Emergency Preparedness =		= Emergency Preparedness =