It’s too early to post-analyse the Hunga Tonga-Hunga Ha’apai eruption. For one, we don’t know whether the eruption itself is finished. But mainly, the real work is still just beginning to understand and respond to what has happened. Tonga is still assessing the impacts, urgent relief operations are just getting into gear, operational scientists and emergency management professionals are still in the thick of things, and much of the Tongan community is still anxiously waiting for news.
And yet, since the whole world has been talking about something other than the pandemic, it’s probably a really good time to say some things that can be said now. Here are five things that I think will hold true after the wash-up.
1. The quality of remote sensing observations has been astonishing. At least four operational geostationary weather satellites (from Japan, the USA, Korea, and China) observed the eruption from their respective positions 36000 km above the equator, tracking the eruption in real time and with multichannel imagery at resolutions of around 1 km and every 10 minutes. At least one of these satellites (NOAA’s GOES-17) captured part of the peak phase of the eruption at 1-minute intervals, with a likely record cold cloud temperature of -105.18 C. Meanwhile, other instruments on a variety of satellites tracked the stratospheric gas (and ash) clouds, and measured the maximum height of the column (at least 35 km at time of writing, twice as high as a tropical thunderstorm tends to get). The observations are so much better than during the largest and highest (40 km) eruption so far recorded on satellite, Mount Pinatubo in 1991. At that time, the Japanese GMS-4 satellite had imagery at hourly intervals and single-band infrared resolution at 5 km, which was fantastic for its time. Had we had the current quality of imagery back then, we would have seen so much more.
Data like this doesn’t just happen. The work of the remote sensing and international meteorological community to steadily develop satellite instruments and techniques, and to share the data with neighbours has been incredible, passionate, and very, very fruitful. Launching a satellite is a major enterprise, but the pay-off for the world’s community is enormous.
2. Lives were saved on the ground through warnings and response. We’ll hear much more about what went right, and what went wrong. This was the kind of event that nobody wants to have to deal with in their lifetime and must have been (and continue to be) very stressful for Tonga’s professional warning and emergency management community. However, we know that both the Tongan Meteorological Service and Tonga Geological Services were actively distributing information and the public were highly attuned to the eruptions in the days leading up to the 15th, with a tsunami warning issued on the 14th and then another warning and a mass evacuation on the 15th. Of course, there will be things that could have been improved, but, like any such extreme event, this is an opportunity for us to pause, admire, and be grateful for the job that the warning and response community do all day and night across the world.
3. Ground and sea observations matter. Operational tide gauges, deep sea buoys, barometers, upper-air soundings and the like all played their part in tracking the tsunami and forecasting the path of the ash and gas cloud. But there is much more that can be done. Many of the regions’ active or potentially active volcanoes are poorly monitored, if at all. Meteorological observational networks are patchy at best through the region, a situation that directly affects the quality of weather forecasting in the rest of the world. Sustainable, long-term solutions are needed in this space, such as the recently launched Systematic Observations Financing Facility, a global multi-agency effort to spread the load of taking weather and climate observations. How will we implement this effort successfully? How will we eventually ensure that all other needed earth system observations, including marine and seismic observations, are sustainably taken and their data shared?
4. Multi-hazard early warning systems shouldn’t be just talk. Through the UN Sendai Framework for Disaster Risk Reduction 2015-2030, we, the people of the world, have signed up to a target to ‘substantially increase the availability of and access to multi-hazard early warning systems and disaster risk information and assessments to people by 2030’. That’s pretty soon, and a multi-hazard event like this volcanic eruption shows us how far we have to go. Our tsunami warning systems are focused on earthquakes, not volcanoes, although the volcanic risk has been known since at least when the 1883 eruption of Krakatau killed 36,000 people. Countries around the Pacific Rim worked hard to make their systems work in this event, but there is much work to do. Our volcanic ash system for aircraft, the International Airways Volcano Watch, operated during this event and has come a long way since its inception in the 80s, but there is no global equivalent for the sea and the ground, with countries largely left to their own devices other than through bilateral partnerships. There’s a lot more we could do to support the world’s volcanologists to help achieve a functional global set of multi-hazard early warning systems. Even relatively mature warning systems, such as tropical cyclone (hurricane, typhoon) warning systems, suffer from inconsistent definitions and approaches between countries. To handle every natural hazard event seamlessly, we’ve got a lot of connecting up and data sharing between disciplines, countries and systems to do.
5. Investments into these areas are worthwhile, no matter how you measure them. Everybody knows that it’s good diplomacy to help your neighbours. However, if you do it well (genuinely helping them in long term partnerships rather than dumping a bunch of useless gear), the benefits can flow far beyond your mutual borders. This is particularly true for monitoring, forecasting, and warning for natural hazards. Typically, for example, investments into meteorological services have a return of around ten dollars for each dollar invested. However, strategic investment in areas that need it can yield much more – for example a recent World Bank study conservatively estimated a global benefit to cost ratio of over twenty-five for investing in surface meteorological observations in data-sparse regions such as the Pacific. One under-appreciated fact of meteorology is that, if observations are improved anywhere in the world, the whole world benefits, since everything in the atmosphere is inter-connected. Taking and sharing better observations in the SW Pacific, for example, would directly improve weather forecasts across the region and create at least several hundred millions of dollars per year in annual benefits.
Hunga Tonga-Hunga Ha’apai dramatically underlined all of this for us. As the atmospheric shock waves continue to ring around the world, as we start to look at how the tsunami travelled across the oceans, and as we start to respond to Tonga’s needs, we have been reminded that, just like in a pandemic, we really are all in this together. And, as we grieve for the victims of this disaster and support the relief effort, there are also plenty of longer term things to do in response.
(first published on LinkedIn on 19 January 2022)