Among Yellowstone National Park's various geothermal basins, the Norris Geyser Basin just might be the most colorful, and it's long been accepted that it's the hottest. But how hot is it?

The U.S. Geological Survey can tell you, thanks to a network of monitors that is taking the basin's temperature.

This past summer USGS staff installed the monitors so scientists and the general public will have daily data -- in most cases 24 hours after it's recorded -- on what’s happening in one of the continent’s most active geyser basins. The network went live in late September and has been automatically transmitting temperature measurements from geysers and hot springs in the basin.

The system was paid for through the American Recovery and Reinvestment Act. Back in April 2009 Interior Secretary Ken Salazar announced that the five USGS Volcano Observatories would share $15.2 million to help upgrade their monitoring of volcanics across the West, in Alaska, and in Hawaii, including within Yellowstone, Mount Rainier, Hawaii Volcanoes, and Lake Clark national parks.

But why wire the Norris Geyser Basin to take its temperature? Well, the basin is the most active in Yellowstone, and keeping tabs on its behavior could come in handy for both educational and public safety needs.

According to a USGS release, the 10 radio-equipped sensors were installed at different spots within the geyser basin, recording temperatures within runoff channels from geysers, hot pools, soils, and even air. The data are saved by the sensors and are then transmitted daily via small radios and the Internet back to the USGS offices in Menlo Park, California, where they are archived, plotted and distributed to the public on the Yellowstone Volcano Observatory website.

You can read more about the project and its significance, and find links to data being collected from sites near Constant Geyser, Echinus Geyser, Steamboat Geyser, Opalescent Spring, Porkchop Geyser, and a few other runoff channels and soil sites, at this site.

While the data generally isn't available for 24 hours after it's recorded, USGS technicians can prompt the monitors to provide measures for scientists in real-time.

The information will help scientists track temperature changes in local streams that might correlate with seismic tremors, the USGS said in a release.

“This innovative use of new technology will allow the public, park staff, educators, and scientists to observe temperature variations in Norris Geyser Basin, one of Yellowstone’s more dynamic geyser basins,” said Henry Heasler, Yellowstone's resident geologist.

While the park has in the past tracked the basin's temperature variations, those sensors are unable to transmit the data, making it necessary to send technicians out to collect the information.

Another interesting aspect of this project is the equipment involved. According to the USGS, the sensors had to be small, with unobtrusive antennas so that the equipment could be placed beneath boardwalks and within small rock piles. And the sensors' radio signal had to be strong enough so that a day’s worth of temperature data could be sent nightly to a base station up to half-a-mile away.

And, of course, the equipment had to be able to withstand acid waters, steam, and sub-freezing temperatures during Yellowstone’s winters.

“We’ve tried to make the system as robust as possible,” said Jake Lowenstern, the scientist in charge of the Yellowstone Volcano Observatory. “If an antenna fails, the loggers should be able to keep recording and hold on to their data for about a month, and then send all their information once we get out to fix the equipment.”

The equipment was purchased from Marathon Products, Inc. of San Leandro, Calif, with funds provided by the American Recovery and Reinvestment Act. Typically, the company’s sensors are installed in refrigerated trucks and warehouses monitoring food and other perishable commodities that require controlled environments, the USGS said.

The temperature-sensor network is part of increased monitoring of Yellowstone by the USGS and its YVO partners at the University of Utah and Yellowstone.

The Yellowstone Volcano Observatory is one of five volcano observatories run by the USGS Volcano Hazards Program to issue timely warnings of potential volcanic hazards.