At Boston College, we operate an AS1 seismograph using the AmaSeis recording and display software. The AmaSeis screen is displayed in the hallway of the Department of Geology and Geophysics (Figure 1). We developed a simple web tool that also displays the AmaSeis screen on the Internet in near-real time. Our goal was to make the web tool as simple as possible, so that anyone running AmaSeis could use this tool if they have an Internet connection. In particular, we wanted it to work without having to pass through a "firewall", which many institutions have and which limits this type of real-time viewing. Like AmaSeis, this web tool works on a PC running Windows 95/98.
While the first author was busy trying to figure out how to accomplish this task, he noticed that his (at the time) eleven-year-old son (the second author) had written HTML code to create a web cam display on his website (www.weirdhat.com). It then occured to the father that this web cam software was essentially what he needed. Together, then, we developed a three-step method: (1) Capture the screen to a file, (2) Upload that file to a server with FTP commands, and (3) Display the file using HTML code.
Here we describe the web tool that we developed. To see the working version
click here.
To keep things as simple as possible, so we chose to use QuickBasic, FTP, and HTML. We begin the process by automatically saving the AmaSeis screen with a screen capture program. There are many screen capture programs available on the Internet, and some are freeware. We chose to use a freeware program called Groone's Kwik Pik (available at www.groonesworld.com). We run AmaSeis with the window maximized, and we set the program to save the screen to a file called seismograph.gif every five seconds. There is an option in KwikPik to send the GIF file to a server via FTP, but we chose instead to save it to a file on our recording computer because that gave us more control over how we use the FTP commands.
We wrote a simple QuickBasic program that uploads the file to a web server every 10 minutes, via FTP. The QuickBasic code is shown in Figure 2, and that code uses commands in a file (ftp_info.txt) that the user creates. A generic example of the ftp_info.txt file is shown in Figure 2. The user needs to modify the ftp_info.txt file so that it contains the appropriate username, password, and directories. An executable version of the QuickBasic program (called loop.exe) can be downloaded by clicking here. To run the program, type loop www.yoursite in the DOS command window. The server has an HTML page that has the file seismograph.gif displayed, and that automatically reloads every 60 sec. The HTML code can be seen by viewing the source code of the file EarthMoves.html. With these components working together, the AmaSeis screen is displayed on the Internet and is updated every 10 minutes.
Examples of our AmaSeis Internet display for days when we recorded significant
earthquakes are shown for the January 13, 2001 El Salvador earthquake, the January
26, 2001 Bhuj, India earthquake, and the April 4, 2001 Plattsburgh, NY earthquake
in Figures 3, 4
and 5, respectively.
For information about other web based projects and computer animation, see
www.weirdhat.com. For information about
various aspects of seismology, with a focus on earthquakes in the eastern United
States, see www2.bc.edu/~kafka.
