Seismology Instruction with the AS 1

Extract Event Screen Overview

     The highlighted portion of the trace is displayed in this window.  To zoom in again, 

highlight the record and click the extract icon below the Menu Bar.

Time Expansion expands the x axis.  For example, when the time expansion is 2, 

the time axis is doubled in length allowing you to zoom in.  In this case only the fi rst 

half of the waveform is displayed.  To see more of the waveform use the scroll bar 

at the bottom of the screen.

   The cursor position is linked to the time on the seismic record and the amplitude 

which is useful for determining periods and amplitude for magnitude determination.

Play Record replays the data recording.  This is useful to point out when arrivals are 

coming in when reviewing an event with students.

   Load a previously saved event or a SAC fi le using the Open Icon. 

The Pick Arrivals Icon is used to mark wave arrivals.  Mark 

either the P and S wave arrivals or the P and Surface wave arrivals.  

The 

Travel Time Curves Icon is used to determine the distance from 

            the event to your station using the time delay between wave arrivals. 

The 

Fourier Transform Icon is used to analyze the frequency content of the 

 seismogram.

Menu Bar

Open 

Event Information

Return to 

Helicorder 

Screen

Amplitude at Cursor Position

Time at Cursor Position (UTC)

Amplitude (y axis)

Replay data recording

Time Expansion

Minutes (x axis)

AmaSeis Version 1.0 Level 2005.05.19

4.6