Randomly blowing up in Spain from google?

Hi all,

We noticed a big uptick in Spanish users during the last few days, and looking at all referrer data it seems to be coming from Google. However, Google isn't telling us that we're getting a lot of search traffic (the total amount of search queries is 5% of the page views we're seeing) - how can I be sure that this is the correct channel, and any tips on maintaining it so that it doesn't die out after a week?

For reference, we normally get about 25 pageviews per day with www.google.com as the referrer, and from 2/13 to today we've gotten 120, 280, 200 (so far). Our site also doesn't yet rank for keywords with significant traffic.

Thoughts appreciated!