Congress has expressed interest in federal programs and activities addressing tsunami detection, warning, research, education, and outreach because of the tsunami hazard to the United States, particularly to Pacific Northwest, Northern California, Alaska, and Hawaii, as well as regions of the Caribbean and Atlantic coastline. The Japanese tsunami of March 11, 2011, illustrated the potential for damage and loss of life posed by a potential tsunami in the Pacific. A fault system off the northwestern United States, called the Cascadia Subduction Zone, is similar to the fault system responsible for the 2011 Japanese tsunami disaster. Oregon, Washington, Northern California, Hawaii, and Alaska all face some risk if the Cascadia fault ruptures. Congress passed the Tsunami Warning, Education, and Research Act of 2017 as Title V of P.L. 115-25 , on April 4, 2017; President Trump signed the bill into law as P.L. 115-25 on April 18, 2017. Title V of P.L. 115-25 amends P.L. 109-479 , Title VIII, the Tsunami Warning and Education Act, which was enacted on January 12, 2007. The new law does not make fundamental changes to the federal government's tsunami activities, which include tsunami forecasting and warning, mitigation, and research, as well as other tsunami-related activities. However, it does broaden the purposes of the federal activities, increasing focus on tsunami research, promoting community resilience to tsunami hazards, and refining requirements for standards and guidelines to improve education and outreach activities and tsunami mapping and modeling. The new law authorizes appropriations of $25.8 million per year for FY2016 through FY2021. An ongoing question for the U.S. tsunami program and related activities is whether Congress will appropriate funds matching the amounts authorized in P.L. 115-25 to carry out the existing program as well as the new activities and priorities in the law. Another challenge is how Congress should evaluate the effectiveness of the program. A perennial issue for NOAA is keeping its constellation of Deep-Ocean Assessment and Reporting of Tsunami (DART) buoys operational, and the new law specifies a goal of keeping at least 80% of the buoy system operational at all times. More generally, because Title V of P.L. 115-25 adds an emphasis on research throughout the program, a future question is how well research results are incorporated into tsunami resilience, education, warning, and other activities. Also, damaging tsunami events are relatively rare for the United States, so it is difficult to assess the overall effect of tsunami program activities on an annual basis. If a large and damaging tsunami were to strike the United States, an additional challenge for Congress would be to sort out how effective the program was at reducing the amount of damage and the number of injuries and fatalities. In addition, the bill repeals P.L. 109-424 , the Tsunami Warning and Education Act, also passed by the 109 th Congress. P.L. 109-424 was signed into law by President George W. Bush on December 20, 2006, and is nearly identical to P.L. 109-479 . P.L. 115-25 removes any potential for ambiguity by repealing one of the existing laws. This report provides a section-by-section comparison of text quoted from P.L. 115-25 and P.L. 109-479 , shown in Table 1 , with some brief comments from the Congressional Research Service (CRS) pointing out selected changes and how those changes affect P.L. 109-479 and the tsunami activities it authorized (far right column of Table 1 ). The table is organized so that the same or most similar sections, and parts of sections, are in the same row or rows. The CRS comments generally address the sections or parts of sections in the same row of the table.

Summary: The National Oceanic and Atmospheric Administration's (NOAA's) National Weather Service (NWS) manages two tsunami warning centers, which monitor, detect, and issue warnings for tsunamis. The NWS operates the Pacific Tsunami Warning Center (PTWC) at Ford Island, HI, and the National Tsunami Warning Center (NTWC) at Palmer, AK. The tsunami warning centers monitor and evaluate data from seismic networks and determine if a tsunami is likely based on the location, magnitude, and depth of an earthquake. The centers monitor relevant water-level data, typically with tide-level gauges, and data from NOAA's network of Deep-Ocean Assessment and Reporting of Tsunami (DART) detection buoys to confirm that a tsunami has been generated or to cancel any warnings if no tsunami is detected. In the 114th Congress, the House passed legislation amending U.S. tsunami activities (H.R. 34) and the Senate passed similar legislation (Title V of H.R. 1561). However, the 114th Congress did not enact a final version of the legislation. The 115th Congress passed the Tsunami Warning, Education, and Research Act of 2017 as Title V of P.L. 115-25 on April 4, 2017. The bill was signed into law on April 18, 2017. Title V of P.L. 115-25 amended P.L. 109-479, Title VIII, the Tsunami Warning and Education Act, which was enacted on January 12, 2007. The new law does not make fundamental changes to the federal government's tsunami activities, which include tsunami forecasting and warning, mitigation, and research, as well as other tsunami-related activities. However, it does broaden the purposes of the federal activities, increasing focus on tsunami research, promoting community resilience to tsunami hazards, and refining requirements for standards and guidelines to improve education and outreach activities as well as tsunami mapping and modeling. The new law authorizes appropriations of $25.8 million per year from FY2016 through FY2021. An ongoing question for the U.S. tsunami program and related activities is whether Congress will appropriate funds matching the amounts authorized in P.L. 115-25 for NOAA to carry out the tsunami program. Another challenge is how Congress should evaluate the effectiveness of the program. Because Title V of P.L. 115-25 adds an emphasis on research, a future question is how well research results are incorporated into tsunami resilience, education, warning, and other activities. More generally, if a large and damaging tsunami were to strike the United States, an additional challenge for Congress would be to sort out how effective the program was at reducing the amount of damage and the number of injuries and fatalities. This report compares the enacted legislation text with P.L. 109-479, Title VIII, section by section, with brief comments on selected comparisons about how changes in P.L. 115-25, Title V, affect P.L. 109-479, Title VIII, and the authorized tsunami activities.