# Before the wave arrives — why USGS and NOAA matter ## Learning purpose Help the learner explain why the United States maintains taxpayer-funded earthquake monitoring and tsunami-warning systems for rare, potentially catastrophic events. Connect a historical example to detection, ocean measurement, warnings, and community action. The live USGS map is an optional investigation after the lesson. ## Start with the question “Why maintain a warning system on days when nothing disastrous happens?” Destructive tsunamis are uncommon. NOAA/NWS gives a worldwide historical average of roughly two events per decade that cause damage or deaths on distant shores. That is not a timetable or a prediction. [NOAA/NWS: about tsunamis](https://www.weather.gov/safety/tsunami-about). ## Three historical examples The death estimates count different things. Do not treat them as a consistent ranking of tsunami-only deaths. | Example | Evidence to use | Source | |---|---|---| | Alaska, March 27, 1964; M9.2 | NOAA lists 124 tsunami deaths, including losses in Alaska, California, and Oregon. The event helped lead to an Alaska warning facility in 1967. | [NOAA event and animation](https://sos.noaa.gov/catalog/datasets/tsunami-historical-series-alaska-1964/) | | Indian Ocean, December 26, 2004; M9.1 | NOAA’s 2024 compilation lists 227,899 dead or missing and presumed dead. Earthquake and tsunami tolls cannot be separated reliably. | [NOAA historical compilation (PDF)](https://www.ncei.noaa.gov/sites/default/files/2024-11/IO_Poster_20241030_final_lowres.pdf) | | Japan, March 11, 2011; M9.1 | More than 18,000 died or remained missing and presumed dead in the combined disaster. NOAA credits warning and evacuation systems with limiting loss of life outside Japan. | [NOAA event analysis](https://www.ncei.noaa.gov/news/day-2011-japan-earthquake-and-tsunami) | The Indian Ocean lacked a regional warning system in 2004. [NOAA-hosted research](https://www.pmel.noaa.gov/public/pmel/publications-search/search_abstract.php?fmContributionNum=4987) discusses the gaps in warning and ocean observation. Use this case to connect instruments, communications, and preparedness. Explore the event’s reach to U.S. coasts with [NOAA’s Pacific-wide 2011 animation](https://sos.noaa.gov/catalog/datasets/tsunami-historical-series-japan-2011/). ## How the agencies and communities work together The page contains these eight actual source images, with visible captions and full-size links: - **Figure 1 — Tsunami formation:** the original four-stage image from the Ocean Institute, modified by NOAA/NWS. It explains water displacement, waves crossing the ocean, and coastal changes. [Image](../assets/tsunami/noaa-tsunami-formation.jpg) · [NOAA/NWS source](https://www.weather.gov/nthmp/guide). - **Figure 2 — Kodiak, 1964:** a photograph of damaged vehicles and boats on the waterfront. Credit: USGS Alaska Technical Data Unit, SF-GP-00-0107, public domain. [Image](../assets/tsunami/usgs-kodiak-1964.jpg) · [USGS record](https://www.usgs.gov/media/images/tsunami-damage-kodiak-alaska). - **Figure 3 — Natori, 2011:** wreckage after the Japan earthquake and tsunami. Credit: Bruce Jaffe, USGS, public domain. [Image](../assets/tsunami/usgs-natori-2011.jpg) · [USGS record](https://www.usgs.gov/media/images/wreckage-after-japan-earthquake-and-tsunami-2011). - **Figure 4 — The Pacific model:** NOAA/PMEL visualization of the March 2011 Japan tsunami. Colors show modeled maximum deep-water amplitudes in centimeters; they are not coastal flood depths or current alerts. Ask the learner to locate Japan, Hawaii, and the U.S. West Coast. [Image](../assets/tsunami/pmel-japan-2011-wave-model.jpg) · [Bernard et al. (2023), opening illustration](https://tos.org/oceanography/article/50-years-of-pmel-tsunami-research-and-development) · [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Reproduced unchanged. - **Figure 5 — The warning system:** NOAA/NWS’s original diagram connects observations with warning centers, emergency managers, and the public. [Image](../assets/tsunami/noaa-warning-system.jpg) · [NOAA/NWS source](https://www.weather.gov/nthmp/guide). Do not imply that officials must wait for ocean confirmation before issuing an initial warning. - **Figure 6 — The DART cutaway:** NOAA/PMEL illustration of a pressure recorder, acoustic link, surface buoy, and satellite connection to shore. The labels for warning centers are historical. Ask the learner to trace the measurements and identify equipment that needs continuing maintenance. [Image](../assets/tsunami/pmel-dart-cutaway.jpg) · [Bernard et al. (2023), Figure 2](https://tos.org/oceanography/article/50-years-of-pmel-tsunami-research-and-development) · [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Reproduced unchanged. - **Figure 7 — A DART surface buoy:** an actual NOAA photograph extracted from page 2 of the saved 2024 modernization announcement. A separate seafloor pressure recorder supplies measurements. [Image](../assets/noaa-dart-buoy.png). - **Figure 8 — Seismic fieldwork:** a 2019 seismometer installation at Ridgecrest, California. Credit: Elizabeth Cochran, USGS, public domain. This is broader earthquake monitoring, not a dedicated tsunami installation. [Image](../assets/tsunami/usgs-ridgecrest-installation.jpg) · [USGS record](https://www.usgs.gov/media/images/seismometer-installation-ridgecrest-california). The separate **budget chart** shows the FY2024 Earthquake Hazards Program appropriation for monitoring, assessment, and research; NOAA spending is separate. It was drawn for the lesson using USGS data. Use “death estimate” or “amount” for numbers. Refer to Figures 1–8 only for the actual images listed above. [Complete image credits](../assets/tsunami/credits.md). 1. **USGS and seismic partners:** rapidly locate and measure earthquakes. This information supports NOAA’s assessment. [USGS: the partnership](https://www.usgs.gov/faqs/there-a-system-warn-populations-imminent-occurrence-a-tsunami). 2. **NOAA and ocean-observing partners:** DART instruments and coastal gauges measure the water response. [NOAA: detection](https://www.tsunami.noaa.gov/pmel-theme/tsunami-detection). 3. **NOAA/National Weather Service warning centers:** evaluate evidence, model coastal impacts, and issue or revise tsunami alerts. Initial alerts may precede ocean confirmation. [NOAA: forecasts and warnings](https://www.tsunami.noaa.gov/pmel-theme/forecast-warning). 4. **Emergency managers and communities:** communicate and act on warnings through preparation and evacuation. [NOAA/NWS: preparedness](https://www.weather.gov/safety/tsunami-before). These activities overlap; they are not a rigid sequence in which NOAA always waits for a buoy measurement before warning anyone. Earthquake magnitude alone does not establish tsunami impact. USGS does not issue the tsunami warnings. [USGS PAGER FAQ](https://earthquake.usgs.gov/data/pager/faq.php). Ask: “What would be missing if we had earthquake instruments but no ocean instruments? What would still be missing if we had both but no effective communication or evacuation plan?” ## What taxpayers fund Both agencies operate or support sensor networks with partners. Sustained public funding supports equipment, communications, maintenance, analysis, research, and trained people. NOAA’s warning centers monitor year-round. [NOAA: continuous readiness](https://www.ncei.noaa.gov/news/great-alaska-earthquake). The page gives two dated examples of substantial expenditure: - **USGS:** approximately **$62.6 million** appropriated by Congress for FY2024 ANSS earthquake and crustal-deformation monitoring and reporting; the source table reports $62.645 million. This includes broader earthquake functions. [USGS decadal strategy, table 1, printed page 8](https://pubs.usgs.gov/circ/1544/cir1544.pdf). [Saved report, PDF page 20](../assets/sources/usgs-earthquake-strategy-2024-2033.pdf#page=20). - **NOAA:** a **$30 million** DART equipment-modernization investment announced in May 2024. This is a specific upgrade project, not an annual operating budget. [NOAA announcement](https://www.noaa.gov/news-release/biden-harris-administration-invests-30m-to-improve-tsunami-ocean-observing-system). [Saved announcement (PDF)](../assets/sources/noaa-dart-modernization-2024.pdf). The full FY2024 Earthquake Hazards Program appropriation in the USGS table is $92.651 million: $16.376 million for hazard and risk assessment, $13.630 million for targeted research, and $62.645 million for ANSS monitoring and reporting. Monitoring accounts for about two-thirds of that program. These are appropriations, not an audit of actual spending. The table's caption says 2020–23, but its column headings and surrounding text explicitly include FY2024; use the 2024 column. Do not sum these into an annual tsunami budget or call them current-year expenditures. USGS seismic networks also support earthquake response, shaking alerts, engineering, and hazard research; they do not exist only for tsunami warnings. [USGS ANSS mission](https://www.usgs.gov/programs/earthquake-hazards/science/anss-mission). Discussion: “What evidence should we use to judge the value of maintaining this capability, beyond counting disasters in one quiet year?” ### What the instruments measure - **Ground motion:** the Global Seismographic Network has approximately 150 stations, operated through the USGS/NSF/EarthScope partnership and affiliates. This is one network, not a count of every seismic station. [USGS GSN overview](https://www.usgs.gov/programs/earthquake-hazards/gsn-global-seismographic-network). - **Deep-ocean water changes:** NOAA operates and maintains 39 DART systems. A seafloor pressure recorder and surface buoy work together to report passing waves. This is the NOAA network, not the worldwide total. [NOAA detection](https://www.tsunami.noaa.gov/pmel-theme/tsunami-detection). - **Coastal water levels:** tsunami-capable NOAA tide gauges report each minute. These observations help refine coastal forecasts. [NOAA tide-gauge account](https://oceanservice.noaa.gov/news/sep25/tide-gauges-tsunami-response.html). Learners can open the [NOAA station map](https://tidesandcurrents.noaa.gov/tsunami/) themselves. ### What continuing support pays for The DART II design sends seafloor measurements acoustically to a buoy, then by satellite to shore. Its battery power, moorings, recovery operations, and backup electronics illustrate the physical work behind the data. Use the [NOAA engineering paper](https://www.pmel.noaa.gov/tsunami/Dart/Pdf/mein2836_final.pdf) for design context, not current network counts or disaster tolls. USGS identifies station calibration, upgrades, and sustained maintenance as priorities. [USGS laboratory strategy, 2026](https://pubs.usgs.gov/publication/cir1563/full). NOAA assigns ongoing checks of communications, calibration, buoy position, and battery condition. [NOAA data-management responsibilities, printed page 21](https://repository.library.noaa.gov/view/noaa/50015/noaa_50015_DS1.pdf). Forecasting also requires staff, computing, and maintained models; funding must support the connected operation. The $30 million NOAA announcement covers replacement of aging DART equipment under a contract awarded to SAIC. Its 2025–2028 replacement schedule was a plan announced in 2024, not proof of present completion. The lesson does not establish a total annual NOAA tsunami operating budget or a cost per buoy. ### A recent example of the benefit NOAA reports that the July 2025 Kamchatka tsunami response gave the U.S. West Coast 8–12 hours of lead time; Crescent City ordered evacuation hours before arrival. [NOAA's event account](https://oceanservice.noaa.gov/news/sep25/tide-gauges-tsunami-response.html). That distant-event example is not a minimum warning time for nearby tsunamis. Ask: “Choose one maintenance job. How could neglecting it affect the evidence available to a warning center?” Do not invent a precise lives-saved or dollar-savings calculation. ## Explain the possible benefit carefully The lesson draws this inference: in a severe event threatening populated U.S. coasts, timely warnings and effective evacuation could save many thousands of lives. Actual benefits depend on the event, warning time, exposure, and people’s ability to respond. This is a potential benefit, not a measured or guaranteed U.S. lives-saved total. Distinguish the historical evidence from the forward-looking conclusion. Higher-hazard U.S. areas include Alaska, Hawaii, the West Coast, and Pacific and Caribbean territories. [NOAA/NWS: coastal hazards](https://www.weather.gov/safety/tsunami-hazards). ## Keep natural warnings in the lesson Nearby waves can arrive before an official alert. In a coastal hazard zone, strong or long shaking, unusual ocean movement, or an ocean roar can be a natural warning. Protect yourself during shaking, then move safely along evacuation routes to high ground or inland without waiting for an official alert. Use current [NOAA/NWS safety guidance](https://www.weather.gov/safety/tsunami-during) for details. Current alerts come from [NOAA’s U.S. Tsunami Warning Centers](https://www.tsunami.gov/), not this learning page. ## Optional live-data investigation The learner can open the live section to request an official USGS M2.5+ or M4.5+ day/week GeoJSON feed directly in the browser. No key or backend is needed. They may select or pin two earthquakes, compare magnitude and depth, and add observations. The feed shows reported earthquakes, not tsunami alerts or ocean measurements. A quiet feed is not an all-clear. Do not predict earthquakes or infer tsunami status from it. [USGS GeoJSON documentation](https://earthquake.usgs.gov/earthquakes/feed/v1.0/geojson.php). The site preserves feed-generation and retrieval timestamps, source URLs, review status, magnitude type, and longitude/latitude/depth. It displays failed requests and labels any retained snapshot. Marker size indicates magnitude; color indicates depth. Natural Earth supplies the bundled world outline. ## Return to BoodleBox The history cards are for reading. In the response section, the learner chooses a historical event beside the questions, writes their answers, and selects **Prepare my BoodleBox response**. This opens text to review, copy, and paste into their BoodleBox chat; nothing is sent automatically. It works even without live data and includes the historical example, reflections, knowledge-check selections, and any available live-data comparison. Treat their answers as learner claims. Do not claim to see their browser or receive results automatically. Ask one useful follow-up: check the agency roles, distinguish disaster totals from tsunami-only deaths, or help connect public investment to preparedness. Keep retrieval quiet unless asked. The public lesson contains reference material, not the visitor’s current answers. References reviewed September 4, 2026. ## Guided investigation update — September 5, 2026 The main page now presents a five-stop guided investigation. Use [tsunami-investigation.md](tsunami-investigation.md) for the current teaching sequence and checkpoint interpretation. This document remains the factual reference; its figures and longer lesson are available under “Explore the full lesson, figures, and sources.” The new sequence uses case and step URL parameters and saves notes locally by case. Older reference-section notes remain valid discussion material.