Not everyone can afford Earthquake alarm. But something is always better than nothing. Even if you don't have earthquake alarm you can use this method to get quick SMS/email alert after an earthquake comes.
Go to https://sslearthquake.usgs.gov/ens/ and you'll be greeted like this.
Here sign up for the service after which you can configure your alert, i.e. choose which location you like to receive alert for and what magnitude of earthquake.
From now on right an earthquake you'll receive an email. In the screenshot above you can see that I got SMS after an earthquake of more than 5.0 in magnitude for my country Nepal.
To receive SMS, in the email form use +email@example.com, if you're Ncell user from Nepal. For Nepal Telecom user go to nearest shop and buy yourself a SIM card with better service i.e. Ncell.