Webicorder Viewer


The webicorder viewer allows you to download and view webicorder plots, or seismograms, from various different sources and hopefully makes the whole process less fraught than going out to the web directly for them.

The main seismograms used are those you can get through the IRIS QuackQuery interface and are from instruments that are to be found in the _REALTIME virtual network. When you first load the system the current list of over 2000 stations will be loaded along with over 8000 pieces of channel data. For the few who used the old version note that this is very different now. I will deal with loading the data at the end.

This is a big topic and this page deals with the IRIS stations on the first tab only. See links below for the other tabs and for more advanced functions.

view-menu-liteAll version of QVS Data have this facility and the Lite and Standard versions are only slightly different for the Pro versions.

In all versions the form is reached from the same point on the View menu, or by holding down the Ctrl key and pressing W.

The screen you will see is this. (Click it for a larger image)

webicorder-main-form

OK, it won’t be exactly like this because the list probably won’t be filled (I may add some sample ones however). The stations/channels in the lists are ‘favourites’, one you have decided you wish to have handy.

Normally you would enter the details in the 4 boxes and then click on ‘View Plot’ to see the seismogram. That is if you like a potted version. But it has much more to it than just that. First let us explore the boxes.

Name of the station? Maybe I should change that to the code for the station. We will work with a station here as an example called MGOD. MGOD is found up in the Aleutian Islands and is in the AV network. So first problem is how do we know that? There are two places you can find the information. The first is on the IRIS DMC Metadata Aggregator site. [→] All of the information for the stations on the first tab comes from this source. I am not going to explain how to use this tool as you have a much simpler method available to you that is in the program.

Find buttonIf you click on the binoculars this will take you to the station selector. The advantage of this second method is that, provided it is not too out of date, the stations in the list are all ones that are in the _REALTIME virtual network when you last downloaded the list and therefore should have data available.

Note however that these publicly available webicorder / seismograph stations do change from time to time and the list can slowly get out of date.

The form when it opens looks like this:

Station search form

If you know the name or part of the name or description of a seismo you can search for the one you want.

Well you are right but you can search for something.

Unfortunately the lists compiled by IRIS are not exactly search friendly since they are not used for that purpose. You are looking for GOD – no, not The Divine Being – the seismo station. Type in god and click the binoculars. You should get two stations returned from this search, the second one being the one you want.

If you click on the line for AV.MGOD and then click on the blue arrow, or simply double-click the line, the details will be found in the lists on the left hand side and it will be set up ready to select the channel. In this case there is only the one channel available which is EHZ.

The ‘Load Selected’ button puts the details into the 4 boxes and you can then change the date or plot type if you wish to. The ‘Display Selected’ button also puts the details into the 4 boxes, but then displays the image if it is available. Don’t forget that this is going out to the web so must have a connection available and the speed of retrieval will depend upon the speed of your connection.

webicorder-main07_r201507

Of course the image displayed here I have kept small so that it can at least be seen what it is. Normally you would run this full screen, but even then a full page seismogram will not fit the page. You can make it fit using the ‘Fit’ button on the toolbar.

You can also magnify the plot several times (about 10x from memory) and you can shrink it as well. Clicking on 100% just returns it to its original downloaded size.

Here is part of a plot:

And here it is at full magnification:

Another way of finding the seismogram you want is to enter the latitude and longitude of the event and let the system find the closest station for you. In order not to run away and get stuck in a loop the number of increments the program will look for a station is 20. Each increment is 0.5 degrees of latitude or longitude. You cannot guarantee to find a station inside a 10 degree but 10 degree box, but there is a good chance.

In the image below I have entered the latitude and longitude from this quake:

2011-10-06 11:12:29, -24.181, -64.250, 6.2, 9.5, Jujuy. Argentina

You can either enter them as shown with both in the larger box and separated by a comma, or one in each of the boxes. Then hit the binoculars and you should get the result below.

As you can see it found the observatory in Chile. You should at this point be aware that the data for realtime displays is not kept for long. Some stations it is only seven days. Most it is for around 14 days, but there are the odd one or two where it is held for much longer.

If you have some items in your favourites lists you can double-click one and the plot will be loaded, and the station/network code will be entered in the 4 boxes so you can change dates.

You can achieve the same by highlighting the line in the favourites list and then clicking on ‘View Plot’ BUT there is a slight difference here. This only works if the boxes are clear, in other words the content of the boxes takes priority. Say you double click a line. The codes will be entered and the seismo displayed. If you now single click a line and click view plot the current one will be re-displayed because the View Plot button always reads the boxes first. You can either use clear, or just double click another line.

To save a station as a favourite use the ‘Add To Favourites’ button on the toolbar.

Toolbars 01

I have found a station in Australia that I want to add to the second tab (NZ/AU). Just a quick note on the three tabs. They are yours to do with as you wish. I tend to use the first for the US, the second for NZ/AU and the third for other areas but the choice is entirely yours. By the way you can name these tabs in the settings.

You will see this dialogue box when you click ‘Add To Favourites’

If you go ahead the system will then find the name of the station from it’s records and display it for you to accept or alter.

If you click on OK the station is added to the selected list and sorted alphabetically.

Page last updated July 2015

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