Saga number 1? - Safe prefectures?

The end of 2025 saw a jump in seismic activity around the ring of fire; it became increasingly more active and there were multiple earthquakes including many with higher magnitudes. The tsunami alert after Russia’s earthquake covered multiple countries skirting the pacific and typhoons overstayed their usual timeslots and were larger in nature.

In summary the ring of fire is an area which circles the Pacific Ocean there are many tectonic plates here causing increased volcanic activity and earthquakes. 75 percent of the worlds active volcanoes live in this area and 90 percent of global earthquakes happen within this area. It is also where you can find the deepest trench in the world the Mariana as an interesting side note. During geography class I recall the teacher using biscuits and custard to demonstrate tectonics I do not recall being able to eat the biscuits and custard after, however. The ring of fire includes many subduction zones where a plate will push down on another these heavier plates slide under lighter ones causing seismic activity.  

In the west of the Pacific Ocean/ ring of fire another natural disaster also can be found the typhoon. These usually occurring during a specific period and during my stay in Japan I was always given a heads up to when typhoon season would begin. 2025 saw typhoons well after the usual season.

Japan is one of the countries within the ring of fire and is one of the most seismically active countries in the world. It sits upon the intersection of four tectonic plates and accounts for up to 20 percent of the world’s earthquakes measuring above magnitude 6. Japan is home to 111 active volcanoes of which 50 are constantly monitored on average it experiences 15 volcanic events yearly. It also finds itself within the path of many typhoons in short Japan is a very active on the natural disaster front. This is also one of my longest introductions to a blog I have written in a while. Today’s main topic is the top ten safest prefectures in Japan.

On a whim on day, I decided to ask Chat GPT to rank the prefectures based on their safety from natural disasters using recorded disasters and any data relating to safety. It spat out a list placing Saga prefecture finally as number one for something other than ugliest prefecture to live in. Amused by this is decided to do some digging as we know Chat GPT isn’t always the most reliable. After spending about an hour researching the ring of fire, checking out hazard maps for Japan and looking at other lists ranking safest prefectures. after seeing the same prefectures coming up repeatedly, I decided to list 6 which topped out most charts. On a side note, I had an immensely fun time researching for this list and enjoyed looking at the hazard maps and even the Nankai trough worst case scenario data models, so I hope this blog is an interesting read for many.

In no order these are 6 prefectures that are safer than most. These shouldn’t be taken as anything rock solid (pun fully intended), but I will list reasons for why they are safer than most. I am considering natural disasters including volcanoes, earthquakes, typhoons, flooding and landslides. I also write this after one of the prefectures on the list just experiences a 5.7 magnitude earthquake yesterday so take it with a pinch of salt.

Saga

Topping Chat GPTs list and because I am bias to where I live, we will start with Saga prefecture. Saga is located centrally within Kyushu and has a shield around it in the form of mountains. These mountains protect Saga from extreme weather. It sits on the Sea of Japan meaning its less exposed to tsunamis which are often generated on the pacific side where the ring of fire is. Because of this it experiences low seismic activity. It sits in the middle of two active volcanoes however far enough away to be directly affected by any volcanic activity. It is generally out of most typhoon paths.

I researched tsunamis and Saga awhile back trying to find historical evidence and often drawing blanks for anything major. When I asked my coworkers about natural disasters my most amusing reply was Saga has nothing (long dramatic pause) to be proud of. But it has nothing to fear either. The consensus being Saga generally is safe; the biggest threat I could find on the hazard maps is flooding if a 30-meter wave hit and the power plant up near Karatsu. The power plant was built up there because of the low seismic activity.

In the past Sagas north side has had tsunami alerts issued especially in the case of the recent Noto earthquake. Because of this it remains alert and has precautions in place adding to its safety ranking. Saga has put in place safety measures in the north and has evacuation plans for northern cities such as Imari and Karatsu. Whilst the threat is not a 0 it is safer than most.

Shiga

Often an overlooked prefecture within the Kansai area, Shiga is home to lake Biwa Japan’s largest lake. The lake makes up a large part of the prefecture, about 1/6th of the prefecture is taken up by the lake. The lake is also freshwater, meaning if for any reason the prefecture was shut off from water supplies it would not have to go far to find water. It is located centrally and is also protected by mountains. All hail mountain shields! It is outside of typhoon paths and doesn’t experience major tsunamis due to it being landlocked. Shiga has no access to the sea eliminating one of the threats that many other prefectures have to plan for. It was found that only 1 percent of earthquakes in Japan occurred within Shiga making it safer than most.

Whilst Shiga does have active volcanoes these are not a direct threat to any major city, interestingly Mt. Kusatsu-Shirane has an acidic crater lake making it cool because I deem it so. Shiga like Sagas most likely threat is flooding caused by rain areas near mountains may experience landslides. Because of these factors it is found often in rankings of safest prefectures.

Gunma

Home to a free all you can eat Konjac buffet Gunma prefecture is beautiful and boasts many beautiful onsens and ryokans. Being landlocked Gunma does not experience tsunamis as it has no coastal area, and it is usually outside of typhoon paths. The prefecture does sit within an earthquake prone area it has safety precautions in place because of this. Gunma sits on ancient ash and lava flows making the ground stable. Gunma doesn’t experience much flooding and in general doesn’t experience extreme weather.

Because I have read the words volcano and earthquake a lot over the research and writing of this blog, I decided to mention some minor threats that Gunma has experienced that are unique and provided a break from the usual. Gunma had a minor water poisoning incident in a small town non were harmed but it raised caution about water safety. The prefecture has also recently had several bear sitings spurring a need for caution. But other than these and the earthquake prone zone Gunma is relatively safer than most.

Tottori

Located along the Sea of Japan Tottori is home to Japan’s sand dunes, extensive beaches and has been described as Japan’s Australia. Over 100 years of monitoring, this prefecture has ranked the lowest for earthquakes measuring over 5 magnitudes. Like Saga its coastal areas face the Sea of Japan meaning it doesn’t experience tsunamis generated on the southern more active fault. Most of these prefectures coastal area is sand dunes meaning if a tsunami occurred the human cost would be lower. Tottori is home to a beautiful stratovolcano named Mt. Daisen that resembles fuji thus earning it the name Hoki Fuji. However, Mt. Daisen is dormant meaning it has a lower volcanic threat than the other 111 volcanoes mentioned in the opening.

Tottori’s biggest threat again is flooding and strong winds it also experiences cloud bursts adding to the flood susceptibility. It is important to note this prefecture as of yesterday experienced a 5.8 magnitude earthquake. While this is a safe prefecture and it has ranked the lowest over 100 years it does not mean its immune to them just that they are less frequent in comparison. With most of Tottori being sand any earthquake in the dessert will be less damaging due to sand but most casualties occur within manmade areas and Tottori’s towns are where most of the people are. The prefecture has precautions in place making it still safer than most.

Kagawa

Located on the Seto Sea inlet facing Hiroshima and Okayama, Kagawa is home to beautiful beaches and aquariums. Kagawa is mostly outside of Typhoon paths and experiences infrequent seismic activity. Unlike the other prefectures on this list this prefecture is at a very high risk of disaster should the Nankai trough experience a mega thrust. Generally, the prefecture is at less risk of tsunamis as it faces inwards but in the case of a mega thrust the island of Shikoku would suffer a lot of damage. Kagawa is very prepared with this in mind and there are many emergency plans in place. In recent years the weather has grown more unpredictable but at most this prefecture wasn’t as much risk of flooding.

Historically however this prefecture has experienced stable weather conditions and very few major earthquakes and tsunamis. The area facing inland is key and another huge bonus like Saga the prefecture doesn’t have any active volcanoes being it is not at risk of volcanic activity.

Okinawa

This may be an odd choice to include on the list as Okinawa is often hit by typhoons laying within the typhoon path however because this risk is so frequent the prefecture itself is highly prepared. Like how because Japan is seismically active the newer buildings here are shock proof or how because snow is so infrequent in the UK despite our northern position the entire country somehow shuts down at the sight of one flake. How often a disaster occurs will also reflect how much precautions and measures will be taken. Okinawa is less prone to severe earthquakes however it does still experience them.

Whilst Okinawa does have underwater active volcanoes and a few on land ones some areas would not be directly affected from any volcanic eruption. The weather in Okinawa is mild and often it experiences heat waves and droughts. But because these are frequent again Okinawa is very prepared and has robust plans in place. Due to Okinawa’s location away from the mainland in the case of a mega thrust it could potentially escape major damage, but it is impossible to predict. Overall Okinawa is here mainly because it is very prepared.

To conclude it is often impossible to predict natural disasters and as we have seen with Tottori even if historically a prefecture has ranked low for earthquakes it doesn’t make it immune and caution should always be taken. However, in comparison and with historical data these prefectures often rank lower when compared to the other prefectures. this blog was very interesting to write, and I ended up on several tangents whilst researching which I enjoyed. I hope this provides an interesting read.