1910 New Zealand Seismicity

 Earthquakes in Aotearoa-New Zealand in 1910

The decade from 1910 to 1919 (hereafter referred to simply as the 1910s) is a relatively understudied period for New Zealand seismicity. Although not as poorly studied as the late 19th century - namely the decades since widespread European colonisation of Aotearoa began in 1840 - the first three decades of the 20th century are not as well studied as the sources available could allow. Nevertheless, with the exception of the far south of the country (Southland and Otago), almost all of the significant earthquakes (local magnitude >6.5) are documented in one form or another, as are several smaller earthquakes which caused damage over a regional, or at minimum district, extent.

As of 2022 there are eleven known earthquakes which afflicted Aotearoa during the 1910s. These range in magnitude from Ms (surface-wave magnitude) 4.9 up to Mw (moment magnitude) 7.3. These eleven events can be found using the National Earthquake Information Database (hereafter referred to as NEID) on the GeoNet website. Of these, nine can be found in Eiby's "Annotated List of New Zealand Earthquake[s]" (1968), and eight can be found in Downes & Dowrick's "Atlas of Isoseismal Map of New Zealand Earthquakes" (2014, available on CD via GNS webshop; alternatively the 1st edition, 1995, can be found here, documenting only three of the known events).

The earliest of these known, documented events occurred in October 1911 (Mw 5.6, Hastings, Hawke's Bay), and the last in November 1918 (Mw 6.7, Puysegur Bank, SW of South Island; Doser et al., 1999). Three earthquakes in the NEID are not found in Downes & Dowrick (2014), and two are not found in Eiby (1968); these are the February 1914 "Kapiti Coast" earthquake (Ms 4.9; found in Eiby, 1968, only); the February 1918 "Marlborough" earthquake* (M 5.5, NEID only); and the aforementioned November 1918 Puysegur Bank earthquake (Mw 6.7, Doser et al., 1999 only). 

Therefore no seismicity has been documented for the year 1910, nor for 1915, 1916 or 1919. In the past month I have painstakingly recorded the previously undocumented seismicity of the 1910s into my "All Quakes Database". This utilised the online repository of archive newspapers Papers Past (part of the National Library of New Zealand), as well as digitised copies of the archived Seismological Observatory Felt Reports as kept by GNS Science. From these individual earthquakes were identified, and where available multiple felt reports and newspaper articles for individual earthquakes have been collated. 

This task is enormous and will be incredible time consuming. As a taster for the process undertaken, and the results achievable, I elected to begin at the start of the decade with the previously completely undocumented year, 1910.

*It should be noted that the 20th February 1918 "Marlborough" earthquake needs significant revision; a preliminary revision of the earthquake, in order to assign it a location within my "All Quakes Database", determines that this earthquake was a deep North Island event, and likely ~M6.0.

 

Summary of 1910

 

The year 1910 is not a noteworthy year for seismicity in Aotearoa-New Zealand. A total of 120 felt earthquakes have been discovered, of which 27 appear to have had a local magnitude in excess of 4.0. The largest earthquake appears to have had, at best, a moment magnitude of ~5.0, and it is challenging to determine which earthquake that may have been.

Eight earthquakes are the most noteworthy. The first occurred on the 9th May 1910 (ML 4.5-5.5) and struck beneath the Cook Strait, with an epicentre about midway between Farewell Spit in the Tasman Region & Opunake in the Taranaki Region, most likely at a shallow depth. 

The second occurred in the morning of the 15th June 1910 (<ML 4.0) and was a swarm of 21 felt earthquakes which likely struck directly beneath Rotorua city or the southernmost waters of Lake Rotorua. These caused some minor contents damage (MM V-VI).

The third occurred on the 24th June 1910 (ML 4.7-5.5) and struck beneath the northern North Island, with an epicentre somewhere within the Western Bay of Plenty, South Waikato or Rotorua districts, most likely with a deep focus of between 100-250km.

The fourth occurred on the 30th July 1910 (ML 4.5-5.0) and struck somewhere beneath the Manawatu, Palmerston North or Tararua districts, most likely with a mid-crustal focus of 20-40km.

The fifth occurred on the 8th August 1910 (ML 4.5-5.0) and struck somewhere beneath the southernmost mountainous regions of the Marlborough Region, likely north of Hanmer Springs with a mid- to deep-crustal focus of 20-70km (perhaps ~50km depth).

The sixth occurred on the 26th September 1910 (ML 4.0-4.5) and struck beneath the Masterton district, likely with a shallow focus and epicentre within 10km of Masterton township. This caused some minor contents damage in Masterton (MM V-VI).

The seventh occurred on the 7th November 1910 (ML 4.0-5.0) and struck beneath the Kaikoura district or just offshore of the Kaikoura Peninsula, likely with a very shallow focus (<12km depth). This caused some minor contents damage and dislodged some bricks from a single shop chimney (MM V-VI).

This was followed by the eighth noteworthy earthquake, and by far the most significant of the year, on the 9th November 1910 (ML 4.5-5.5). This also struck beneath the Kaikoura district or just offshore of the Kaikoura Peninsula, at a very shallow focus (<12km depth). This caused more widespread moderate contents damage, as well as some minor to moderate chimney damage in Kaikoura and its suburbs (MM VI-VII). This was followed by a succession of felt aftershocks in Kaikoura over the following 12 days, with observed intensities from these aftershocks reaching MM V.

In summary, 1910 was a relatively uneventful year, although it did produce at least four damaging earthquakes, with a maximum intensity of MM VII. By the standards of the early 20th century, this would easily rank amongst the quietest years (possibly matched by 1905, 1908, 1923, 1924 & 1927). Nevertheless, it contained a surprisingly strong, if exceedingly brief, earthquake swarm beneath Rotorua, as well as a shallow & damaging earthquake at Masterton, and one of only three discovered damaging local earthquake sequences to afflict Kaikoura prior to the devastating November 14 2016 Mw 7.8 Kaikoura Earthquake.

 

If you wish to see the sources for this analysis, they can be found in this word document here. All Seismological Observatory Felt Reports are omitted as I do not possess the rights to share them myself. If anyone wishes to see them, please contact the GNS Archives who have the rights to share such information.

 

 

List of Earthquakes in Aotearoa-New Zealand in 1910

 

January 1910

January 11 [15:00 NZMT, 03:30 UTC] - Taranaki Region: <M4, depth uncertain

Reported felt in "Taranaki" (New Plymouth?). No intensity information available.

January 11 [20:30 NZMT, 09:00 UTC] - Hawke's Bay Region, ML 4.0-5.0, mid-crustal focus (33km fixed depth)

Felt in Napier, Hastings, Waipawa & Waipukurau. No intensity information available.

January 17 [10:00 NZMT, 23:00 UTC Jan 16] - Central Hawke's Bay district, <M4, depth uncertain

Felt in Waipawa. No intensity information available.

January 20 [01:30 NZMT, 14:00 UTC Jan 17] - Hawke's Bay Region, ML 4.0-5.0, possible deep focus (40-70km?)

Felt in Napier & Hastings, slight at Wellington. Likely intensity MM IV at Napier & Hastings, MM III-IV in Wellington.

January 24 [23:20 NZMT, 11:50 UTC] - Rangitikei district, <M4, depth uncertain

Felt in Marton. No intensity information available.

February 1910

February 2 [11:05 NZMT, 23:35 UTC Feb 1] - Gisborne Region, <M4?, depth uncertain

Felt in Gisborne, slight. No intensity information available.

February 11 [11:30 NZMT, 00:00 UTC] - Horowhenua district, <M4, depth uncertain

Felt in Foxton, accompanied by loud report. No intensity information available.

February 14 [06:37 NZMT, 19:07 UTC Feb 13] - Horowhenua district, M4.0-4.5, mid-crustal focus (33km fixed depth)

Felt in Palmerston North, slight at Foxton & Pahiatua. Likely intensity MM IV at Palmerston North, MM III-IV at Foxton, MM III at Pahiatua.

February 14 [13:50 NZMT, 02:20 UTC] - Tararua district, M4.0-4.5, depth uncertain

Felt in Waipawa, Dannevirke, Woodville & Palmerston North. Likely intensity MM IV at Dannevirke & Palmerston North, MM III-IV at Waipawa and Woodville. Palmerston North time is 14:30 NZMT; assumed associated with this event, but could perhaps be a different quake 40 minutes later.

February 22 [23:35 NZMT, 12:05 UTC] - New Plymouth district, M3.5-4.0, shallow focus (5-20km depth)

Felt in New Plymouth, slight at Warea. Likely intensity MM IV at New Plymouth, MM III-IV in Warea.

February 24 [00:30 NZMT, 13:00 UTC Feb 23] - Hastings district, <M4, depth uncertain

Felt in Hastings, slight. Likely intensity MM III-IV.

March 1910

March 1 [21:15 NZMT, 09:45 UTC] - Tararua district, <M4, depth uncertain

Felt in Woodville. Likely intensity MM III-IV.

March 21 [18:00 NZMT, 06:30 UTC] - Wanganui or South Taranaki district, M4.0-4.5, depth uncertain (see below note)

Felt in New Plymouth, Wanganui & Foxton, slight at Otaki. Likely intensity MM IV-V at Wanganui, MM IV at Foxton, MM III-IV at New Plymouth, MM III at Otaki. Felt extent very widespread along South Taranaki Bight coastline, which could be indicative of a deep focus (80-140km depth) earthquake near Patea or Waverley. Wanganui felt report describes quake as "sharp, short, and severe", accompanied by very loud and long rumbling, possibly suggesting long P-wave period before S-wave arrival? Highest intensity at Wanganui may be due to sediment underlying the town.

March 22 [00:30 NZMT, 13:00 UTC Mar 21] - Wanganui district, <M4, depth uncertain

Felt in Wanganui. Likely intensity MM IV-V; felt report indicates "general awakening of those asleep", whilst also describing this quake as "not so severe as one last evening" [March 21].

March 26 [22:30 NZMT, 11:00 UTC] - Gisborne Region, <M4, depth uncertain

Felt in Gisborne, slight. No intensity information available.

March 29 [20:18 NZMT, 08:48 UTC] - Christchurch district, M4.0-4.5, shallow focus (5-20km depth). Doublet

Felt in Rangiora, Kaiapoi, Christchurch & Sumner. No intensity information available. The seismograph at the Magnetic Observatory in Christchurch (now within the grounds of the Christchurch Botanic Gardens, seismograph station no longer existing) recorded two earthquakes, one commencing at 20:18:24 NZMT and ending at 20:18:54, the second commencing at 20:19:36 NZMT and ending at 20:20:12. The second shock had a greater motion on the seismograph. Kaiapoi and Sumner report feeling both shocks.

March 30 [20:58 NZMT, 09:28 UTC] - Wanganui district, <M4, depth uncertain

Felt in Wanganui. Likely intensity MM III.

April 1910

April 3 [23:00 NZMT, 11:30 UTC] - Central Hawke's Bay district, <M4, depth uncertain

Felt in Waipukurau, slight. Likely intensity MM III-IV.

April 9 [Morning, no specific time given, UTC Apr 8] - Horowhenua district, <M4, depth uncertain

Felt in Levin, slight. Likely intensity MM III-IV. Time given as "small hours of this morning."

April 11 [06:25 NZMT, 18:55 UTC Apr 10] - Selwyn district, <M4, shallow focus (5-20km depth)

Felt in Broken River, slight. Likely intensity MM III-IV. Broken River presumably refers to a disused mine on the south bank of Broken River, an upland tributary to the Waimakariri River.

April 12 [05:15 NZMT, 17:45 UTC Apr 11] - Hastings district, <M4, depth uncertain

Felt in Hastings. Likely intensity MM IV.

April 13 [01:39 or 13:39 NZMT, 14:09 UTC Apr 12 or 02:09 UTC Apr 13] - Central Hawke's Bay district, <M4, depth uncertain

Felt in Waipawa. No intensity information available.

April 17 [21:49 NZMT, 10:19 UTC] - Marlborough Region, <M4, depth uncertain

Felt in Picton. Likely intensity MM III-IV.

April 20 [19:30 NZMT, 08:00 UTC] - South Taranaki district, <M4, depth uncertain

Felt in Patea, slight. Likely intensity MM III-IV; article mentions "on the bridge a distinct tremor could be felt for several seconds."

May 1910

May 6 [Morning, no specific time given, UTC May 5] - Queenstown-Lakes district, <M4-4.5, depth uncertain

Felt in Queenstown, slight. Location uncertain; could be a local quake within the district, could be Southland Region in vicinity of Milford Sound with magnitude of M4.0-4.5, or could be southern Westland district south-west of Haast with magnitude of M4.0-4.5.

May 9 [13:04 NZMT, 01:34 UTC] - South Taranaki Bight, M4.5-5.5, shallow to mid-crustal focus (5-40km depth)

Felt in New Plymouth, Opunake, Collingwood & Nelson, slight at Warea, Kaponga & Rahotu. Likely intensity MM IV at New Plymouth, Opunake, Collingwood & Nelson, MM III-IV at Warea, Kaponga & Rahotu. Likely had an unusual epicentral location about midway between Opunake and Farewell Spit. Wide felt extent indicates local magnitude of ~M5.0, with ±0.5 uncertainty.

May 22 [10:00 NZMT, 22:30 UTC May 21] - Tararua district, <M4, depth uncertain

Felt in Woodville, slight. No intensity information available.

May 29 [15:15 NZMT, 03:45 UTC] - Stratford district, <M4, depth uncertain

Felt in Puniwhakau. No intensity information available.

May 29 [15:45 NZMT, 04:15 UTC] - Manawatu-Wanganui Region, magnitude & depth uncertain (see below note)

Felt in Wanganui, slight at Matamau. Likely intensity MM III-IV at Wanganui. Felt report for Wanganui gives 15:44 NZMT, "felt generally by everyone". Article for Matamau gives 15:45 NZMT. These could potentially be separate small (<M4) events, given distance between them and no reports from locations between (e.g. Feilding, Palmerston North, Taihape); alternatively, a larger (M4.0-4.5) event beneath, for example, the Ruahine Range or adjacent Rangitikei valley. The former - two separate events - is easier to reconcile, but the coincidental times leads to uncertainty.

May 31 [19:07 NZMT, 08:37 UTC] - Hawke's Bay Region, M4.0-4.5 (?), depth uncertain

Felt in Hastings, slight at Waipawa. Likely intensity MM III-IV at Hastings. Article for Hastings states, "last night... some describe the shock as severe while others state it was scarcely perceptible", whereas a definitive time but no definitive description is given in the article for Waipawa. As with the May 29 shock, these could potentially be two separate small (<M4) events, or a larger (M4.0-4.5) earthquake between Hastings & Waipawa with a likely mid-crustal focus (33km fixed depth).

June 1910

June 11 [05:00 NZMT, 17:30 UTC Jun 10] - Whakatane district, <M4, shallow focus (5-20km depth)

Felt in Whakatane. Likely intensity MM III-IV.

June 12 [14:13 NZMT, 02:43 UTC] - Wellington Region, M4.0-4.5, shallow to mid-crustal focus (5-40km depth)

Felt in Longbush, Petone & Hutt Valley, slight at Wellington & Gladstone. No intensity information available. Likely epicentral location beneath the Rimutaka Range or southern Tararua Range.

June 15 [01:00-02:00 NZMT, 13:30-14:30 UTC Jun 14] - Timaru district, <M4, shallow focus (5-20km depth). Doublet or triplet

Felt in Geraldine. Likely intensity MM IV. Articles states that the earthquake was "felt by several residents of Geraldine" and that one person "distinctly felt three shocks", & upon awakening another person, they both "felt the final shock." Possible two or three separate, minor (M2.5-3.5) earthquakes in quick succession.

June 15 [05:30-06:30 NZMT, 18:00-19:00 UTC Jun 14] - Rotorua district, <M4, very shallow focus (5-12km depth). Swarm of 21 earthquakes

Felt in Rotorua, Ohinemutu and Whakarewarewa. Likely maximum intensity MMV-VI. A swarm of shocks occurred between 05:30 & 06:30 NZMT, the heaviest reportedly occurring at 06:15 NZMT. Minor contents damage was caused - pictures shaken off walls & some crockery fell from shelves. A few people left their dwellings for safety from falling objects. Likely epicentral location beneath Rotorua city at customary very shallow depths.

June 24 [13:40 NZMT, 02:10 UTC] - North Island (Western Bay of Plenty, South Waikato or Rotorua districts), M4.7-5.5, deep focus (100-250km depth)

Felt in Napier, Woodville, Eketahuna & Nelson, slight at Gisborne, Waipawa & Weber. No intensity information available. Highly unusual sparse distribution of felt reports, particularly for an earthquake during the middle of the day. No felt reports in some major population centres (e.g. Wanganui, Palmerston North, Wellington) as would be expected for most deep focus (100-250km depth) North Island earthquakes. Felt extent surprisingly reaches to Nelson. Best analogue earthquakes from the 21st century are deep earthquakes with epicentres between the Bay of Plenty coast and Lake Taupo, with magnitudes at minimum ML 4.7, up to at most ML 5.5.

June 26 [22:20 NZMT, 10:50 UTC] - Hastings district, <M4, depth uncertain

Felt in Hastings, very slight. No intensity information available.

July 1910

July 6 [06:30 NZMT, 19:00 UTC Jul 5] - Wanganui district, <M4, depth uncertain

Felt in Wanganui. Likely intensity MM IV. Felt report indicates that the earthquake was "felt generally by everyone... general awakening of those asleep."

July 9 [01:24 NZMT, 13:54 UTC Jul 8] - Hastings district, <M4-4.5, depth uncertain

Felt in Napier & Hastings. Likely intensity MM IV. Article describes shock as "sharp and prolonged... disturbed the slumbering town of Hastings." Possibly a small (M4.0-4.5) intermediate focus (40-70km?) earthquake north-west of Hastings?

July 13 [06:40 NZMT, 19:10 UTC Jul 12] - Cook Strait, M4.0-5.0, depth uncertain

Felt in Wellington & Blenheim, slight at Nelson. Likely intensity MM III-IV in Wellington, Blenheim & Nelson. Confusion exists in newspaper articles; Bush Advocate (Dannevirke newspaper) reports a quake was felt there at 06:40 NZMT, which would probably be a separate earthquake in the Tararua district as intervening locations between Dannevirke & Wellington do not report a felt shock. The Inangahua Times (Reefton) reports a "sharp shock" felt in Christchurch, but no Christchurch newspapers report such an occurrence.

July 18 [03:45 NZMT, 16:15 UTC Jul 17] - Gisborne Region, <M4, depth uncertain

Felt in Gisborne. Likely intensity MM IV-V; felt report indicates "felt generally by everyone; general awakening."

July 19 [00:15 NZMT, 12:45 UTC Jul 18] - Tararua district (?), M4.0-4.5 (?), depth uncertain

Felt in Waipawa & Feilding. Likely intensity MM IV in Waipawa & Feilding. Articles give slightly differing times (00:15 NZMT at Waipawa, 00:30 NZMT at Feilding). These could possibly be separate events, or alternatively a small (M4.0-4.5), possibly mid-crustal focus (20-40km depth) earthquake beneath the Ruahine Range. Two separate events may be the easier of the two to reconcile.

July 27 [18:40 NZMT, 07:10 UTC] - Hastings district, <M4, depth uncertain

Felt in Hastings. No intensity information available.

July 30 [02:15 NZMT, 14:45 UTC Jul 29] - Manawatu-Wanganui Region, M4.5-5.0, mid-crustal focus (33km fixed depth)

Felt in Taihape, Waipawa, Waipukurau, Piripiri, Raumati, Dannevirke, Wanganui, Woodville, Palmerston North, Pahiatua, Ngaturi, Foxton & Eketahuna. Likely intensity MM IV at all, possibly MM IV-V at Dannevirke & Taihape. Likely earthquake origin is a mid-crustal (20-40km depth) earthquake beneath the Manawatu, Palmerston North or Tararua districts.

July 31 [15:00 NZMT, 03:30 UTC] - Hawke's Bay Region, M4.0-4.5, depth uncertain

Felt in Napier, slight at Wairoa. No intensity information available. Likely epicentral location in Hawke Bay, north-east of Napier.

August 1910

August 1 [08:59 NZMT, 21:29 UTC Jul 31] - Kaikoura district, <M4, depth uncertain

Felt in Kaikoura. Likely intensity MM III-IV. Felt report states "slight rattle of windows... only felt by persons not in motion."

August 7 [18:10 NZMT, 06:40 UTC] - Napier district & environs, <M4, depth uncertain

Felt in Napier, slight. No intensity information available.

August 8 [14:15 NZMT, 02:45 UTC] - Marlborough Region, M4.5-5.0, mid- to deep-crustal focus (20-70km depth)

Felt in Hawera, Nelson, Havelock, Mahakipawa, Cullensville, Picton, Blenheim, Westport, Reefton & Hanmer Springs, slight at Motueka & Christchurch. Likely intensity MM IV at Nelson, MM III-IV at Blenheim; no other intensity information available. Felt location are simply referred to as having felt in as "a sharp shock", except for Motueka & Christchurch where it is "a slight shock." The felt extent is quite large (from South Taranaki down to Christchurch), with most felt locations clustered in the upper North Island (Buller district, Tasman, Nelson & Marlborough Regions). This indicates a probable Marlborough Region origin, but with absence of felt reports in Wellington likely not the Marlborough Sounds area. A potentially comparable earthquake has been identified (March 11 2017 South Marlborough, ML 4.9, Mw 4.4, 50km focal depth). An earthquake was recorded on the Christchurch Magnetic Observatory seismograph, but does not correlate to this event unless timing on the instrument was out by about 17 minutes (seismogram began at 13:58:12 NZMT, commenced at 14:03:12 NZMT).

August 19 [21:20 NZMT, 09:50 UTC] - Kaikoura district, <M4, depth uncertain

Felt in Kaikoura. Likely intensity MM III-IV. Felt report does not clearly state the effects - simply confirming a set of effects without specifying which were observed ("felt by persons in motion" is MM III-IV; "disturbance of moveable objects, doors, windows" is MM IV)

August 21 [17:00 NZMT, 05:30 UTC] - Tararua district, <M4-4.5, depth uncertain

Felt in Woodville and Eketahuna. No intensity information available. A Wairarapa newspaper believed the earthquake had only been felt in Eketahuna, stating as much two days after a Woodville newspaper reported it was felt there.

September 1910

September 4 [04:45 NZMT, 17:15 UTC Sep 3] - Dunedin district, <M4, shallow focus (5-20km depth)

Felt in Port Chalmers, Dunedin, South Dunedin, Portobello & Sawyers Bay. Likely intensity MM IV. Described as "preceded by a rumbling sound like distant thunder... and then the house shaken", "seemed... much like the passing of a very heavy lorry in the street", "a heavy rumbling caused them to awake... continued tremor produced a creaking in wooden houses." Felt report mentions "disturbance of pictures hanging on walls”, which could possibly indicate MM IV-V in Dunedin.

September 16 [04:18 NZMT, 16:48 UTC Sep 15] - Horowhenua district, <M4, depth uncertain

Felt in Foxton. No intensity information available.

September 19 [01:00 NZMT, 13:30 UTC Sep 18] - South Taranaki Bight, M4.0-4.5, intermediate to deep focus (70-150km depth?)

Felt in New Plymouth, Palmerston North, Halcombe & Kopuaranga, slight at Wanganui & Woodville. Likely intensity MM IV at Palmerston North, Halcombe & Kopuaranga, MM III-IV at New Plymouth, Wanganui & Woodville. Felt report at Wanganui gives a duration of 15 seconds. Location distribution indicates an origin beneath the South Taranaki Bight, perhaps offshore of Waverley or Patea, with a customary depth for this area of ~100km.

September 19 [05:48 NZMT, 18:18 UTC] - Hawke's Bay Region, M4.5-5.0, depth uncertain

Felt in Napier, Hastings, Waipawa, Waipukurau, Dannevirke, Woodville, Pahiatua & Wanganui, slight at Ormondville. Likely intensity MM IV at all. Quite possibly a mid-crustal focus (20-40km depth) earthquake beneath the Central Hawke's Bay district.

September 23 [02:45 NZMT, 15:15 UTC Sep 22] - Hastings district, <M4, depth uncertain

Felt in Hastings. Likely intensity MM IV.

September 26 [14:35 NZMT, 03:05 UTC] - Masterton district, M4.0-4.5, depth uncertain (see below note)

Felt in Eketahuna, Kopuaranga, Tinui, Masterton, Carterton & Longbush. Likely intensity MM V-VI at Masterton, possibly MM IV at remaining locations. Article for Masterton reports some contents damage: "no damage was done beyond the breaking of some crockery, glassware, and such like articles, which fell from shelves." Same article describes the earthquake as "the heaviest felt in Masterton since the big shake in August, 1904..." The August 1904 Mw 7.0-7.2 Cape Turnagain Earthquake produced intensities of MM VII in Masterton (Downes & Dowrick, 2014; Downes 2006). The earthquake was felt throughout most of the Masterton & Carterton districts, but appears to have only caused moderate or strong intensities at Masterton, suggesting an epicentre close to the town & a shallow focus of 10-25km.

October 1910

October 8 [03:00-04:00 NZMT, 15:30-16:30 UTC Oct 7] - New Plymouth district, <M4, shallow focus (5-20km depth)

Felt in New Plymouth. Likely intensity MM IV; "the slumbers of the inhabitants of New Plymouth were disturbed..." states the newspaper article.

October 18 [02:00 NZMT, 14:30 UTC Oct 17] - Ruapehu district, <M4 (?), shallow focus (5-20km depth)

Felt in Waiouru. Likely intensity MM IV. This earthquake was felt in Waiouru during a rather spectacular minor eruption of Ngauruhoe, as observed by those living along the railway line between Waiouru & Taumarunui. The eruption is reported to have begun at about 17:15 NZMT on October 17, with the eruption becoming obscured, presumably from steam and ash emissions at the summit, by 22:21 NZMT. The earthquake seems to have followed observed eruptive activity. The eruption could be observed at Waiouru, Waimarino, Ohakune & possibly Taihape. If the earthquake was directly associated with the eruption, it likely had a very shallow focus (<12km depth).

October 20 [16:30 NZMT, 05:00 UTC] - Napier district & environs, <M4, depth uncertain

Felt in Napier. No intensity information available.

October 21 [00:30 NZMT, 13:00 UTC Oct 20] - New Plymouth district, <M4, shallow focus (5-20km depth)

Felt in New Plymouth. Likely intensity MM IV.

October 21 [12:00 NZMT, 00:30 UTC] - Wanganui district, <M4, depth uncertain

Felt in Wanganui & Foxton. No intensity information available. Article from Wanganui states a 30 second duration, likely exaggerated? Probable origin offshore Rangitikei & Manawatu districts, between Whanganui & Rangitikei River mouths.

November 1910

November 7 [06:23 NZMT, 18:53 UTC Nov 6] - Kaikoura district, M4.0-5.0, very shallow focus (5-12km depth)

Felt in Kaikoura. Likely intensity MM V-VI. Minor contents damage in some stores & hotels, "few minor breakages in glassware & bottled stuffs...", as well as minor damage to a chimney: "a chimney in the back of a fruitshop had a few bricks dislodged." Residents were somewhat startled; felt report states there was "general awakening of those asleep" and that there was spilling of liquids. The shock was described in a newspaper article as the heaviest felt in Kaikoura "since November 16, 1901." The November 1901 Mw 6.8 Cheviot Earthquake produced intensities of MM VI in Kaikoura.

November 9 [19:53 NZMT, 08:23 UTC] - Kaikoura district, M4.5-5.5, very shallow focus (5-12km depth)

Felt in Kaikoura, Greymouth, Cheviot, Waikari, Amberley, Rangiora, Lyttelton, Le Bon's Bay & Akaroa, slight at Blenheim. Likely intensity MM VI-VII at Kaikoura, MM III-IV at Blenheim, Greymouth & Cheviot, MM III at Akaroa, not enough intensity information for Waikari, Amberley, Rangiora, Lyttelton or Le Bon's Bay. Not absence of report from Christchurch, which is puzzling given it was felt at three locations in close proximity and all around the city. 

Moderate damage in Kaikoura, both to contents ("store had a large number of articles shaken off the shelves and smashed", "crockery and bottled stuffs being broken... contents of private houses also suffered" & "crockery etc thrown in all directions") & to chimneys ("several chimneys destroyed", "a number of chimneys partially fallen and otherwise damaged" & "the tops were shaken off a number of chimneys in the town and in the suburbs - several being half down.") These indicate an intensity varying from MM VI to MM VII, with an assessment of MM VII based on the description of chimneys being "half down" possibly being more favourable. Felt report from Kaikoura states that there was spilling of liquids, and the shock lasted only 7 seconds. Outside of Kaikoura the impact was minimal, the earthquake simply being observed. The Post Office clock in Cheviot stopped, but this is only indicative of MM III.

The earthquake had a relatively lengthy aftershock sequence, with 24-25 of these felt in Kaikoura (see below earthquakes). This suggests that the earthquake had an epicentre close to Kaikoura (as no other locations report feeling these aftershocks), and it is quite likely that the sequence -with the November 7 (NZMT) earthquake as a foreshock, this November 9 earthquake as the mainshock, and the subsequent aftershocks - occurred at a very shallow depth. There is, however, no available evidence to assign these earthquakes to any mapped fault.

It is worth noting that the Christchurch Magnetic Observatory seismograph is not reported as having recorded this earthquake. Articles note that the Riverview Observatory seismograph in Sydney began recording "a series of extraordinary earth tremors" at 16:00 local time (06:00 UTC). These were the records of a major (Ms 7.9) earthquake which afflicted Espiritu Santo in the New Hebrides (modern-day Vanuatu); the seismic waves from this large regional earthquake would have likely completely obscured any seismic waves from the far more local Kaikoura earthquake.

November 10 [00:00 NZMT, 12:30 UTC Nov 9] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. Likely intensity MM IV. Only mentioned in a felt report from Kaikoura, duration 2 seconds.

November 10 [02:10 NZMT, 14:40 UTC Nov 9] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. Likely intensity MM IV. Only mentioned in a felt report from Kaikoura, duration 2 seconds.

10 November [05:45 NZMT, 18:15 UTC Nov 9] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. Likely intensity MM IV. Only mentioned in a felt report from Kaikoura, duration 3 seconds.

November 10 [12:26 NZMT, 00:56 UTC] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. No intensity information available.

November 10 [Night NZMT, Morning UTC] - Kaikoura district, <M4, very shallow focus (5-12km depth). Six shocks

Felt in Kaikoura. Likely intensity MM IV (?)

November 11 [02:00 NZMT, 14:30 UTC Nov 10] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. Likely intensity MM V; "only a few small empty bottles upset."

November 14 [14:00 NZMT, 02:30 UTC] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. No intensity information available.

November 14 [Afternoon NZMT, Morning UTC] - Kaikoura district, <M4, very shallow focus (5-12km depth). Four or five shocks

Felt in Kaikoura. No intensity information available.

November 17 [19:45 NZMT, 08:15 UTC] - Central Hawke's Bay district, M4.0-4.5, depth uncertain

Felt in Waipawa, Waipukurau, Weber & Feilding. No intensity information available.

November 19 [10:36 NZMT, 23:06 UTC Nov 18] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. No intensity information available.

November 20 [11:00 NZMT, 23:30 UTC Nov 19] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. No intensity information available.

November 20 [11:00-11:10 NZMT, 23:30-23:40 UTC Nov 19] - Kaikoura district, <M4, very shallow focus (5-12km depth). Two shocks

Felt in Kaikoura. No intensity information available. "Two minor tremors".

November 20 [19:00 NZMT, 07:30 UTC] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. No intensity information available.

November 20 [19:05 NZMT, 07:35 UTC] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. No intensity information available.

November 20 [Night NZMT, Morning UTC] - Kaikoura district, <M4, very shallow focus (5-12km depth). Two shocks

Felt in Kaikoura. No intensity information available. "Two minor earthquakes".

November 21 [08:45 NZMT, 21:15 UTC Nov 20] - Kaikoura district, <M4, very shallow focus (5-12km depth)

Felt in Kaikoura. No intensity information available.

November 22 [02:20 NZMT, 14:50 UTC No 21] - Cook Strait, M4.0-5.0, depth uncertain

Felt in Wellington, Blenheim & Havelock, slight at Otaki & Masterton. Likely intensity MM IV at Wellington, Blenheim & Havelock, MM III-IV at Otaki & Masterton.

November 25 [07:30 NZMT, 20:00 UTC] - Central Hawke's Bay district, M4.0-4.5, depth uncertain

Felt in Waipawa, slight at Woodville. No intensity information available.

November 29 [09:49 NZMT, 22:19 UTC Nov 28] - Manawatu-Wanganui Region, M4.0-5.0, depth uncertain

Felt in Wanganui, Palmerston North, Foxton & Mangahao, slight in Mangaweka, Dannevirke, Feilding & Wellington. Likely intensity MM IV in Wanganui, MM III in Palmerston North, no intensity information available for other locations. Likely origin in vicinity of Foxton, possibly mid-crustal origin (20-40km) or deeper (40-70km) offshore of Foxton.

December 1910

December 10 [12:49 NZMT, 01:19 UTC] - Tararua district, <M4, depth uncertain

Felt in Woodville, slight. No intensity information available.

December 18 [08:10 NZMT, 20:40 UTC Dec 17] - New Plymouth district, <M4, depth uncertain

Felt in New Plymouth. No intensity information available.

December 19 [03:30 NZMT, 16:00 UTC Dec 18] - Hurunui district, <M4, depth uncertain

Felt in Hanmer Springs. No intensity information available.

December 20 [21:05 NZMT, 09:35 UTC] - Wanganui district, <M4, depth uncertain

Felt in Wanganui, slight. Likely intensity MM III. Felt report states duration of 3 seconds.

December 21 [19:25 NZMT, 07:55 UTC] - Selwyn district, <M4, shallow focus (5-20km depth)

Felt in Bealey (Arthur's Pass). Likely intensity MM III-IV. Felt reports states "felt by persons standing... caused rattling of loose roofing iron...", duration 3 seconds

December 21 [21:08 NZMT, 09:38 UTC] - Manawatu-Wanganui Region, M4.0-4.5, depth uncertain

Felt in Taihape, Mangaweka, Waipawa & Waipukurau, slight at Woodville & Palmerston North. No intensity information available. Likely origin beneath the Ruahine Range, beneath either the Manawatu or Tararua districts.

December 22 [21:30 NZMT, 10:00 UTC] - Palmerston North district & environs, <M4, depth uncertain. Suspect event

Felt in Palmerston North. No intensity information. This earthquake is regarded as a potential duplicate of that of December 21, which was also felt in Palmerston North. The time slightly later, and the article is from a newspaper which reported the Dec 21 earthquake previously; however, it does not state the date, making it impossible to ascertain which day this 21:30 NZMT earthquake occurred on. With no way to certify this information, this earthquake is regarded as the only suspect event of 1910.

December 31 [02:30 NZMT, 15:00 UTC Dec 30] - Hurunui district, <M4, depth uncertain

Felt in Hanmer Springs. Likely intensity MM IV.