In the aftermath of last month's catastrophic tsunami came a rising chorus questioning the absence of a warning system. Fueling the furor was news that the seismic monitoring station run by the U.S.'s National Oceanic and Atmospheric

Administration (NOAA) had detected the tectonic shifts and 9.0 seismic shocks, and it had known about the potential for a tsunami. The excuses for not communicating, as quoted in the media, rang hollow: "The Indian Ocean isn't our area of responsibility." "We didn't know who to call." "We made our best effort."

Many people have asked why the countries on the Indian Ocean don't have their own warning system. Yes, seismic activity there is less frequent. But the bottom line is a lack of resources, and poor countries have to make hard choices in allocating their limited funds. Unfortunately, thousands of lives were lost in the technology chasm between the haves and have-nots. The countries hit by the tsunami lack satellites and other communications technology, as well as the engineering know-how to create these systems even if they had money to spare.

We may be the world's only superpower, but our global responsibilities remain unclear. Acting as the world's policeman sometimes earns us as many enemies as friends. But the job of the world's Coast Guard isn't as controversial. We can afford global oceanic monitoring, and there should be no question about putting it into effect. Tens of thousands of lives could have been spared, and hundreds of millions of dollars in relief could have been saved.

We have a moral responsibility to share technology that could save so many lives and prevent so much suffering. U.S. mariners can "Dial-A-Buoy" via their cell phones to get individual wind and wave measurements from the National Data Buoy Center. But our seismic monitoring stations don't even have a list of phone numbers to warn our global neighbors of impending disaster.

Propelled by the weight of this tragedy, momentum is building to implement NOAA's tsunami warning system on a global scale. We should ask all coastal countries to join a coalition to help pay the incremental expenses needed for expansion. We already have a proven infrastructure in place, so monitoring additional tectonic hot spots doesn't mean re-inventing the wheel. Also, as we've recently fine-tuned the electronics of the system, we have some engineering that is definitely worth sharing.

While NOAA has had tsunami warning centers off Hawaii and Alaska since 1967 and 1949, respectively, its Deep Ocean Assessment and Reporting of Tsunamis (DART) came online in late 2003 (see the figure). DART's goal is to improve the capability for early detection and real-time reporting of tsunamis in the open ocean. DART also reduces costly false alarms. For example, an evacuation in Honolulu would cost $68 million in lost business alone.

The DART system consists of anchored sea-floor pressure recorders and companion surface buoys with real-time communications capabilities. The sea-floor sensor detects pressure changes caused by disturbances from earthquakes or other disruptions and transmits the data via acoustic link to the buoy. Data is then relayed via the NOAA GOES satellite to the ground stations, which demodulate the signals and send them on to the Tsunami Warning Centers. NOAA geophysicists can then determine the displacement of water and hence the size of the tsunami, if areas are at risk, and whether a warning is necessary.

Taking this system global isn't just about helping others. It also could mean more resources to further enhance the basic technology. Getting partner countries to invest could mean new design challenges and solutions for the engineers involved. NOAA has agreed that the system should be worldwide.

Expanding the tsunami warning keeps with our global scientific goals as outlined during the first Earth Observation Summit, which the U.S. hosted in the summer of 2003. Since then, almost 50 nations have joined the U.S. in strengthening global cooperation in observing the Earth.

As global citizens, we all benefit from gathering and analyzing geophysical data to monitor changing climatic, geologic, and environmental conditions. The Earth Observation Summit's goal is a global supercomputer that crunches data from a "system of systems" to take the "pulse of the planet." It is truly time to start thinking—and engineering—globally!

For information about NOAA, go to www.noaa.org. To learn more about the Earth Observation Summit and its goals, go to www.earthobservationsummit.gov.