To find information about the development of devices to detect tsunamis for your timeline search tsunami history technology detection in a search engine as a starting point.
These books may be useful. Look for ideas about the questions you need to answer. Check when the book was published and then you will need to search for any scientific improvements in the information you have found in other sources. These might help with your timeline!
Tsunamis by 
Disaster in the Indian Ocean, Tsunami 2004 by When searching use keywords such as detection or prediction tsunamis to begin your search and as you find more information you can search these keywords as well.
Published in May 2015 by the Pacific Tsunami Warning Centre. This video is also available at school on Public:\9 Science\Geology.
When searching use a combination of keywords with tsunamis such as warning systems, building structures, seawalls, tsunami shelters, floodgates and population location.
This article looks at the science behind Japan's quake and tsunami?