Infrasound arrays placed about 6 km from Mount Etna detected 57 of 59 eruptions between 2008 and 2016 and sent alerts roughly one hour ahead (Ripepe et al., JGR Solid Earth 2018). Infrasound is sound below about 20 Hz, too low for human ears, and explosive volcanoes produce a lot of it: one global study detected 62% of 110 eruptive events with at least one station (Dabrowa et al., EPSL 2011). The stakes sit mostly in the sky. The nine Volcanic Ash Advisory Centres (VAACs) issued 13,771 ash advisories to aviation in 2025 (ICAO Consolidated VAAC Management Report 2025), and USGS has documented 79 damaging aircraft encounters with ash between 1953 and 2009 (USGS Data Series 545). We aggregated data from the U.S. Geological Survey, the Alaska Volcano Observatory, ICAO and the VAAC network, EUROCONTROL, the Congressional Research Service, and papers in Science, Nature, Scientific Reports, Frontiers in Earth Science, JGR and the Journal of Volcanology and Geothermal Research. For the treaty-monitoring side of the same technology, see our CTBTO infrasound network statistics; this roundup stays on volcanoes and ash.
TL;DR
- 62% of 110 explosive events at 39 volcanoes were detected by at least one infrasound station (Dabrowa et al., EPSL 2011).
- Infrasound from the 2005 Manam eruption was detected 10,671 km away (Dabrowa et al., EPSL 2011).
- Etna infrasound arrays flagged 57 of 59 eruptions in 2008 to 2016, about one hour ahead (Ripepe et al., JGR Solid Earth 2018).
- A regional method detected and located more than 72% of 61 Bogoslof infrasound events in Alaska (Sanderson et al., JGR Solid Earth 2020).
- Infrasound-derived vent velocities of 50 to 125 m/s reproduced a 10 km Etna plume (De Angelis et al., Scientific Reports 2023).
- The Hunga Tonga plume reached 57 km, into the mesosphere (Proud et al., Science 2022).
- The Hunga Tonga Lamb wave travelled at 318.2 +/- 6 m/s, almost exactly Krakatau’s 318.8 +/- 3 m/s in 1883 (Wright et al., Nature 2022).
- 94 confirmed aircraft ash encounters in 1953 to 2009, 79 of them damaging (USGS Data Series 545, 2010).
- 104,000 flights were cancelled during the 8-day 2010 Eyjafjallajokull crisis (EUROCONTROL STATFOR 2010).
- 35% of alarmed Bogoslof explosions in 2016 to 2017 were first detected by infrasound (Coombs et al., Frontiers in Earth Science 2018).
- About 1,350 potentially active volcanoes exist worldwide, about 500 with historical eruptions (USGS FAQ).
1. Detection Range: How Far Infrasound Hears an Eruption
Infrasound can catch eruptions from another continent, because low-frequency sound loses little energy as it travels through the atmosphere. The flip side is that propagation depends on stratospheric winds, so detection is never guaranteed. In the largest global test, 62% of 110 explosive events at 39 volcanoes reached at least one infrasound station (Dabrowa et al., Earth and Planetary Science Letters 2011). Most recent available data for a global detection rate: Dabrowa et al., 2011.
The USGS now groups distances into bands: local (under 15 km) and regional (15 to 250 km), with the most energetic volcanic sound typically between 0.5 and 20 Hz (USGS Scientific Investigations Report 2024-5062-C). Remote detections beyond that are a bonus, not a design guarantee.
| Metric | Value | Source |
|---|---|---|
| Explosive events detected by at least one infrasound station (global study) | 62% of 110 events at 39 volcanoes | Dabrowa et al., EPSL 2011 |
| Farthest detection in that study (Manam, Papua New Guinea, January 2005, plume over 20 km) | 10,671 km | Dabrowa et al., EPSL 2011 |
| Most energetic frequency band of volcanic sound | 0.5 to 20 Hz | USGS SIR 2024-5062-C |
| Distance bands defined by USGS for volcano infrasound | Local under 15 km; regional 15 to 250 km | USGS SIR 2024-5062-C |
| Distance over which 2019 Stromboli explosion signals were recorded | 3,700 km | Le Pichon et al., Scientific Reports 2021 |
| Indonesian volcanoes watched by one remote array (IS06, Cocos Island), 2012 to 2019 | 11 volcanoes at 1,000 to 2,000 km | Gheri et al., JVGR 2023 |
| Eruption size reliably detected by that remote array under favourable winds | VEI 3 or greater | Gheri et al., JVGR 2023 |
Context: VEI is the Volcanic Explosivity Index, a logarithmic size scale from 0 to 8. Gheri et al. found that smaller, short-lived events were usually missed at 1,000 km and more, which is why remote arrays complement, rather than replace, local stations.
2. Detection Rates and Warning Lead Times
The value of infrasound for aviation is speed: a pressure wave confirms that an explosion has happened before a satellite image or a pilot report does. At volcanoes with nearby arrays, it can do better than confirm. Etna’s dedicated arrays detected 57 of 59 eruptions (96.6%, 57/59) between 2008 and 2016, with automatic alerts about one hour ahead (Ripepe et al., JGR Solid Earth 2018, reported in the AGU release via Phys.org).
Alaska shows the harder case. Bogoslof, a volcano with no local instruments, produced about 70 explosive events in 2016 and 2017. Seismic stations on neighbouring islands were usually first to raise the alarm, but infrasound first detected 35% of alarmed events, and one infrasound pulse arrived 78 minutes before an eruption onset (Coombs et al., Frontiers in Earth Science 2018).
| Metric | Value | Source |
|---|---|---|
| Etna eruptions detected by infrasound arrays about 6 km from the vent, 2008 to 2016 | 57 of 59 | Ripepe et al., JGR Solid Earth 2018 (AGU) |
| Typical alert lead time at Etna | About 1 hour | Ripepe et al., JGR Solid Earth 2018 (AGU) |
| Lead time of the first operational alert, 4 December 2015 | Almost 2 hours | Ripepe et al., JGR Solid Earth 2018 (AGU) |
| Bogoslof alarmed events first detected by infrasound vs by seismic amplitude (RSAM) | 35% vs 60% | Coombs et al., Frontiers 2018 |
| Bogoslof events detected by global lightning network | 26 of 62 (about 40%) | Coombs et al., Frontiers 2018 |
| Bogoslof events with no alarm at all | 4 | Coombs et al., Frontiers 2018 |
| Median delay from event onset to Volcanic Activity Notice (all Bogoslof events) | 37 minutes | Coombs et al., Frontiers 2018 |
| Bogoslof infrasound events detected and located by a remote regional method | More than 72% of 61 | Sanderson et al., JGR Solid Earth 2020 |
Context: RSAM (real-time seismic amplitude measurement) is a running average of ground shaking. Only 4 of 60 Bogoslof notices (7%) went out before an eruption began, so on an unmonitored volcano most warnings are really fast confirmations. The Etna figures come from the AGU summary of the paper; the press release does not give a false alarm total for 2008 to 2016.
3. From Sound to Plume Height and Mass Eruption Rate
Ash dispersion models need two inputs that are hard to measure in real time: how high the plume rises and how much mass leaves the vent per second (the mass eruption rate). Infrasound offers a shortcut, because the sound carries information about the speed of the gas jet leaving the vent. At Etna on 20 June 2021, infrasound-derived flow velocities of 50 to 125 m/s, fed into a plume model, produced column heights of 8 to 10 km, matching a radar-measured maximum of about 10 km (De Angelis et al., Scientific Reports 2023).
Where satellites are blinded by cloud and there are no local stations, distant arrays can still help: Perttu et al. estimated plume heights from infrasound recorded 2,000 to over 5,000 km from the volcano and applied the method to Taal (Philippines) in January 2020 from a station 1,650 km away (Perttu et al., JVGR 2020).
| Metric | Value | Source |
|---|---|---|
| Vent flow velocity estimated from infrasound, Etna paroxysm of 20 June 2021 | 50 to 125 m/s | De Angelis et al., Scientific Reports 2023 |
| Volume eruption rate at those velocities | 1.6 x 10^4 to 3.9 x 10^4 m3/s | De Angelis et al., Scientific Reports 2023 |
| Plume height from model vs maximum measured by X-band radar | 8 to 10 km vs about 10 km | De Angelis et al., Scientific Reports 2023 |
| Time to run one plume model case | Under 1 second | De Angelis et al., Scientific Reports 2023 |
| Distance range of infrasound records used to estimate plume height | 2,000 to over 5,000 km | Perttu et al., JVGR 2020 |
| Shishaldin (Alaska) 2023: paroxysms and plumes reaching 10 to 14 km above sea level | 13 paroxysms; 7 plumes | Mota et al., Bulletin of Volcanology 2026 |
| Shishaldin 2023 peak mass eruption rate | 10^4 to 10^7 kg/s | Mota et al., Bulletin of Volcanology 2026 |
| Bogoslof 2016 to 2017 maximum ash cloud height | 14 km above sea level | Coombs et al., Frontiers 2018 |
Outlier note: Mota et al. report that automated satellite ash detection mostly failed at Shishaldin, and that global lightning networks picked up only 491 flashes across the sequence. That is exactly the gap that acoustic estimates are meant to fill.
4. Hunga Tonga 2022: The Pressure Wave Benchmark
The 15 January 2022 eruption of Hunga Tonga-Hunga Ha’apai is now the reference event for atmospheric acoustics. Its plume reached 57 km, observational evidence of an eruption injecting material straight through the stratosphere into the lower mesosphere (Proud et al., Science 2022). The pressure pulse it launched was a Lamb wave, a wave that hugs the Earth’s surface and spans the whole depth of the atmosphere.
Wright et al. measured that Lamb wave at 318.2 +/- 6 m/s at the surface, within the measurement uncertainty of the 318.8 +/- 3 m/s recorded after Krakatau in 1883, and tracked it at least three times around the planet (Wright et al., Nature 2022). The eruption was also heard far away: audible signals were reported in Alaska, about 10,000 km away (Assink, EGU Seismology blog 2022, summarising Matoza et al., Science 2022).
| Metric | Value | Source |
|---|---|---|
| Maximum plume height | 57 km (lower mesosphere) | Proud et al., Science 2022 |
| Lamb wave surface speed, Hunga Tonga 2022 vs Krakatau 1883 | 318.2 +/- 6 m/s vs 318.8 +/- 3 m/s | Wright et al., Nature 2022 |
| Times the Lamb wave was tracked around the Earth | At least 3 | Wright et al., Nature 2022 |
| Time for the wave to reach the antipode (opposite side of the Earth) | 18.1 hours | Wright et al., Nature 2022 |
| Estimated energy release, Hunga Tonga vs Pinatubo vs Krakatau | 10 to 28 EJ vs about 10 EJ vs about 30 EJ | Wright et al., Nature 2022 |
| Hours during which the plume was the largest single gravity-wave source on Earth | More than 12 | Wright et al., Nature 2022 |
| Distance at which audible sound was reported (Alaska) | About 10,000 km | EGU blog 2022 (Matoza et al.) |
| Pressure amplitude recorded in Utrecht, Netherlands, 16,500 km away | About 1.5 hPa | EGU blog 2022 (Matoza et al.) |
Context: Matoza et al. counted at least four direct (minor-arc) and three antipodal (major-arc) Lamb wave passages in global records; the paper had 76 authors from 17 countries. One EJ (exajoule) is 10^18 joules.
5. Aviation Ash Encounters: What Detection Is Protecting
Volcanic ash is pulverised rock and glass that melts inside jet engines. USGS documented 129 reported incidents between 1953 and 2009, of which 94 were confirmed ash encounters and 79 caused airframe or engine damage (79/94 = 84%) (Guffanti, Casadevall and Budding, USGS Data Series 545, 2010). Most damaging encounters happened within 24 hours of the start of ash production or less than 1,000 km from the volcano, which is precisely the window in which fast acoustic detection matters. Most recent available data for a full damage census: USGS DS 545, 2010.
A joint DLR and USGS update counted 113 encounters in 2010 to 2014, built mostly from 186 reports in EUROCONTROL’s voluntary incident reporting system; 59 were class 0 (smell or haze only) and 18 reached class 2 or 3 (18/113 = 16%), with no class 4 or 5 events (Christmann et al., International Workshop on Volcanic Ash 2015). Severity classes run from 0 (sulphur smell) to 5 (engine failure leading to loss of the aircraft).
| Metric | Value | Source |
|---|---|---|
| Confirmed encounters vs encounters with airframe or engine damage | 94 vs 79 | USGS DS 545, 2010 |
| Encounters causing in-flight engine shutdown | 9 | USGS DS 545, 2010 |
| Average damaging encounters per year since 1976 | About 2 | USGS DS 545, 2010 |
| Eruption size behind nearly half of damaging encounters | VEI 3 (moderate) | USGS DS 545, 2010 |
| Encounters compiled for 2010 to 2014 | 113 (59 class 0, 36 class 1, 12 class 2, 6 class 3) | Christmann et al., IWVA 2015 |
| 2010 to 2014 encounters involving jet aeroplanes | 56 (30 + 13 + 7 + 6 across classes 0 to 3) | Christmann et al., IWVA 2015 |
| Average days per year with potentially lethal ash clouds over Alaska | 4 | Alaska Volcano Observatory FAQ |
| Flights cancelled during the 2009 Redoubt eruption | More than 300 | USGS 2018 threat assessment news release |
The cost of not knowing where ash is shows up in closures. During the 8-day April 2010 Eyjafjallajokull crisis, 104,000 flights were cancelled, 48% of expected European traffic, peaking at 80% on 18 April and leaving about 10 million passengers unable to board (EUROCONTROL STATFOR, Ash-cloud of April and May 2010). Low-cost carriers lost 61% of flights, and a further 7,000 flights were cancelled in May. Pilots report ash and ATC relays restrictions over voice channels, which our air traffic control radio statistics cover in detail.
6. Volcanic Ash Advisory Centres in 2025
Every eruption detected by an observatory, a satellite or an infrasound array ends up as a Volcanic Ash Advisory (VAA), the text bulletin airlines use to plan around ash. The nine VAACs issued 13,771 advisories in 2025, and about 14,000 a year in both 2024 and 2025 (ICAO APAC MET SG/30 IP/03, Consolidated VAAC Management Report 2025). The workload is lopsided: Darwin and Washington, the centres covering Indonesia and much of the Americas, together issued 81.7% of them ((5,669 + 5,582) / 13,771).
The ICAO target is to issue the first advisory within 20 minutes on 95% of occasions. Washington met it on 97% of 970 initial advisories and Darwin on 94% of 434. The report also names the weak link: the November 2025 Hayli Gubbi eruption in Ethiopia, which sent ash to 50,000 ft (flight level FL500), missed the 20-minute mark because the volcano is not monitored and the eruption was detected only by satellite.
| Metric | Value | Source |
|---|---|---|
| Volcanic Ash Advisory Centres worldwide | 9 | NOAA OSPO Washington VAAC page |
| Volcanic ash advisories issued by all VAACs, 2025 | 13,771 | ICAO Consolidated VAAC Report 2025 |
| Advisories issued by VAAC Darwin vs VAAC Washington, 2025 | 5,669 vs 5,582 | ICAO Consolidated VAAC Report 2025 |
| False alarm advisories, all VAACs, 2025 | 3 | ICAO Consolidated VAAC Report 2025 |
| Initial advisories issued within 20 minutes: Washington vs Darwin | 97% (942/970) vs 94% (409/434) | ICAO Consolidated VAAC Report 2025 |
| Years Hayli Gubbi had been dormant before its 23 November 2025 eruption | Over 8,200 | ICAO Consolidated VAAC Report 2025 |
| Update interval for advisories on ash-producing volcanoes, Washington VAAC | Every 6 hours or sooner | NOAA OSPO Washington VAAC page |
Context: the same report notes that VAAC Anchorage’s output from 2 to 17 August 2025 was about 800% above its five-year average, after Krasheninnikov on Kamchatka erupted for the first time in about 600 years.
7. Monitored and Unmonitored Volcanoes
Infrasound only helps where someone has installed a sensor within range, and coverage remains thin. USGS counts about 1,350 potentially active volcanoes worldwide, about 500 of which have erupted in historical time (USGS FAQ, How many active volcanoes are there on Earth?). A USGS working group puts the number of subaerial volcanoes with Holocene eruptions (eruptions in the current geological epoch) at about 1,400 and notes that “a significant number” lack ground-based sensors, leaving more than 60 satellite instruments as the common safety net (USGS SIR 2022-5116, Powell Center Volcano Remote Sensing Working Group).
The United States illustrates the gap at national scale. The 2018 threat assessment ranked 161 volcanoes, 57 of them very high or high threat (USGS SIR 2018-5140), and the National Volcano Early Warning System (NVEWS) five-year plan targeted 34 of those for upgraded monitoring (Congressional Research Service IF11987, July 2025).
| Metric | Value | Source |
|---|---|---|
| Subaerial volcanoes with Holocene eruptions | About 1,400 | USGS SIR 2022-5116 |
| U.S. volcanoes assessed in 2018: very high / high / moderate / low / very low threat | 18 / 39 / 49 / 34 / 21 (161 total) | USGS SIR 2018-5140 |
| Eruptions and episodes of notable unrest at U.S. volcanoes since 1980 | 120 eruptions; 52 unrest episodes at 44 volcanoes | USGS 2018 threat assessment news release |
| Very-high or high threat U.S. volcanoes named for upgraded monitoring | 34 | CRS IF11987, 2025 |
| NVEWS funding authorized for FY2019 to FY2023 | $55 million | CRS IF11987, 2025 |
| Alaska volcanoes active in the last 10,000 years vs the last 300 years | About 90 vs more than 50 | AVO FAQ |
| Average Alaska volcanoes erupting per year | About 2 | AVO FAQ |
Context: a pending Senate bill (S. 1052) would explicitly add infrasound arrays to the NVEWS equipment list, alongside cameras and digital telemetry (CRS IF11987, 2025). Infrasound monitoring of volcanoes shares its frequency band with industrial sources such as wind farms; our wind turbine infrasound statistics show how differently the same band is measured near homes.
Summary: Volcanic Infrasound and Ash Plume Statistics by the Numbers
| Metric | Value | Source |
|---|---|---|
| Explosive events detected by at least one infrasound station (global study) | 62% of 110 | Dabrowa et al., EPSL 2011 |
| Farthest volcanic infrasound detection in that study | 10,671 km | Dabrowa et al., EPSL 2011 |
| Etna eruptions detected by infrasound, 2008 to 2016 | 57 of 59 | Ripepe et al., JGR Solid Earth 2018 |
| Typical Etna alert lead time | About 1 hour | Ripepe et al., JGR Solid Earth 2018 |
| Bogoslof infrasound events detected and located remotely | More than 72% of 61 | Sanderson et al., JGR Solid Earth 2020 |
| Bogoslof alarmed events first detected by infrasound | 35% | Coombs et al., Frontiers 2018 |
| Remote array detection limit under favourable winds (Indonesia) | VEI 3 or greater at 1,000 to 2,000 km | Gheri et al., JVGR 2023 |
| Infrasound-derived vent velocity, Etna 2021 | 50 to 125 m/s | De Angelis et al., Scientific Reports 2023 |
| Shishaldin 2023 peak mass eruption rate | 10^4 to 10^7 kg/s | Mota et al., Bulletin of Volcanology 2026 |
| Hunga Tonga plume height | 57 km | Proud et al., Science 2022 |
| Hunga Tonga Lamb wave speed | 318.2 +/- 6 m/s | Wright et al., Nature 2022 |
| Hunga Tonga pressure amplitude recorded 16,500 km away (Utrecht) | About 1.5 hPa | EGU blog 2022 (Matoza et al.) |
| Audible Hunga Tonga sound reported in Alaska | About 10,000 km away | EGU blog 2022 (Matoza et al.) |
| Confirmed aircraft ash encounters, 1953 to 2009 | 94 (79 damaging) | USGS DS 545, 2010 |
| Share of expected European flights cancelled on the worst day, 18 April 2010 | 80% | EUROCONTROL STATFOR 2010 |
| Aircraft ash encounters compiled for 2010 to 2014 | 113 | Christmann et al., IWVA 2015 |
| Flights cancelled, April 2010 Eyjafjallajokull crisis | 104,000 (48% of expected traffic) | EUROCONTROL STATFOR 2010 |
| Volcanic ash advisories issued worldwide, 2025 | 13,771 | ICAO Consolidated VAAC Report 2025 |
| Potentially active volcanoes worldwide | About 1,350 | USGS FAQ |
| U.S. volcanoes named for NVEWS monitoring upgrades | 34 | CRS IF11987, 2025 |
Methodology and Sources
- Dabrowa, Green, Rust and Phillips, A global study of volcanic infrasound characteristics and the potential for long-range monitoring, Earth and Planetary Science Letters 2011
- USGS Scientific Investigations Report 2024-5062-C, Infrasound for Volcano Monitoring (Lyons et al.)
- Le Pichon et al., Using dense seismo-acoustic network to provide timely warning of the 2019 paroxysmal Stromboli eruptions, Scientific Reports 2021
- Gheri et al., Monitoring of Indonesian volcanoes with the IS06 infrasound array, JVGR 2023
- Ripepe et al., Infrasonic Early Warning System for Explosive Eruptions, JGR Solid Earth 2018 (AGU release via Phys.org)
- Coombs et al., Short-Term Forecasting and Detection of Explosions During the 2016-2017 Eruption of Bogoslof Volcano, Alaska, Frontiers in Earth Science 2018
- Sanderson et al., Remote Detection and Location of Explosive Volcanism in Alaska With the EarthScope Transportable Array, JGR Solid Earth 2020
- De Angelis et al., Assessment of eruption source parameters using infrasound and plume modelling, Scientific Reports 2023
- Perttu et al., Estimates of plume height from infrasound for regional volcano monitoring, JVGR 2020
- Mota et al., Satellite observations, plume dynamics, and volcanic lightning from the 2023 eruption of Shishaldin Volcano, Alaska, Bulletin of Volcanology 2026
- Proud, Prata and Schmauss, The January 2022 eruption of Hunga Tonga-Hunga Ha’apai volcano reached the mesosphere, Science 2022
- Wright et al., Surface-to-space atmospheric waves from Hunga Tonga-Hunga Ha’apai eruption, Nature 2022
- Assink, EGU Seismology Division blog 2022, on Matoza et al., Science 2022
- Guffanti, Casadevall and Budding, Encounters of aircraft with volcanic ash clouds, 1953-2009, USGS Data Series 545 (2010)
- Christmann, Nunes, Schmitt and Guffanti, Recent Encounters of Aircraft with Volcanic Ash Clouds, DLR and USGS, IWVA 2015
- EUROCONTROL STATFOR, Ash-cloud of April and May 2010: Impact on Air Traffic (STATFOR/Doc394, 2010)
- ICAO APAC MET SG/30 IP/03, Combined APAC VAAC Management Report with the Consolidated VAAC Management Report 2025 (July 2026)
- NOAA Office of Satellite and Product Operations, Washington VAAC
- Alaska Volcano Observatory FAQ
- USGS FAQ, How many active volcanoes are there on Earth?
- USGS SIR 2022-5116, Optimizing satellite resources for the global assessment and mitigation of volcanic hazards (Pritchard et al., 2022)
- USGS SIR 2018-5140, 2018 Update to the U.S. Geological Survey National Volcanic Threat Assessment (Ewert, Diefenbach and Ramsey)
- USGS news release, Which U.S. Volcanoes Pose a Threat? (December 2018)
- Congressional Research Service IF11987, The National Volcano Early Warning and Monitoring System (updated July 29, 2025)
- Data watch: global volcano counts depend on definition. The USGS FAQ gives about 1,350 potentially active volcanoes, the same FAQ page also quotes a 2016 USGS figure of about 1,550, and the Powell Center report uses about 1,400 subaerial Holocene volcanoes; we cite each with its own definition. The AVO FAQ says more than 80 jets have been damaged by ash and seven suffered engine failure, while USGS DS 545 lists 79 damaging encounters and 9 in-flight engine shutdowns to 2009; we use DS 545 as the primary count. Coombs et al. describe Bogoslof as about 70 events but some passages use 64, and Sanderson et al. compare against 61 infrasound-detected events. The Etna 57 of 59 figure is taken from the AGU summary because the journal PDF was not accessible; it gives no false alarm total. EUROCONTROL’s headline of about 100,000 cancellations, the 104,000 total for 15 to 22 April, and the CFMU count of 101,127 use different baselines. Several core datasets are old: Dabrowa et al. (2011), USGS DS 545 (2010) and Christmann et al. (2015) are the most recent available global studies of their kind. A decade-long review of volcanic events observed by the IMS infrasound network for 2011 to 2020 (Matos et al., Research Square preprint, April 2026) appeared in April 2026 and should add newer global detection statistics once peer reviewed.
- Last updated: October 25, 2026. We update this roundup quarterly, and the next refresh is expected when the ICAO Consolidated VAAC Management Report for 2026 is presented to the IAVW and regional MET meetings in 2027.