Þeistareykir
Seismicity by period · derived statistics from Skjálftalísa (Icelandic Met Office)
Status (automatic)
No particular signs of unrest in the last 24 hours — 2 earthquakes recorded, within the system's normal range. Volcano is in normal, non-eruptive state.
VONA = Volcano Observatory Notice for Aviation; the official Met Office colour code for aviation. Independent of Skjálfti's automatic analysis.
Volcanic system in the Northern Volcanic Zone with a geothermal power station. Last erupted millennia ago. (overview — more at vedur.is) · circle on the map = rough outline of the system (radius).
📜 Did you know?
Beneath Þeistareykir in the Northern Volcanic Zone lies a powerful geothermal field that drives a 90 MW geothermal power station (commissioned 2017). Crystals in the Borgarhraun lava have become a natural laboratory: they show that the magma rose from the Earth's mantle, from more than 20 km depth, in only days to months (Mutch et al., 2019).
Historical eruptions in the system — points colored by size, blue circle shows where we are now in time.
Points = earthquake locations in the selected window, coloured by magnitude: M3+ · M2+ · smaller (a sample if more than 800).
Earthquakes
2
Largest
M0.1
M3,0+
0
Depth range
0–0 km
Earthquakes over time
Cumulative count · 2 earthquakes · total moment ≈ M0.2 · count moment
Depth (0 km at top). Grey: fixed depth.
Not enough depth data.
Magnitude distribution
Earthquakes
3
Largest
M0.1
M3,0+
0
Depth range
0–5 km
Earthquakes over time
Cumulative count · 3 earthquakes · total moment ≈ M0.4 · count moment
Depth (0 km at top). Grey: fixed depth.
Magnitude distribution
Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.
Earthquakes
3
Largest
M0.1
M3,0+
0
Depth range
0–5 km
Earthquakes over time
Cumulative count · 3 earthquakes · total moment ≈ M0.4 · count moment
Depth (0 km at top). Grey: fixed depth.
Magnitude distribution
Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.
Earthquakes
16
Largest
M1.2
M3,0+
0
Depth range
0–15 km
Earthquakes over time
Cumulative count · 16 earthquakes · total moment ≈ M1.4 · count moment
Depth (0 km at top). Grey: fixed depth.
Magnitude distribution
Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.
Earthquakes
42
Largest
M1.2
M3,0+
0
Depth range
0–22 km
Earthquakes over time
Cumulative count · 42 earthquakes · total moment ≈ M1.6 · count moment
Depth (0 km at top). Grey: fixed depth.
Magnitude distribution
Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.
Earthquakes
89
Largest
M1.4
M3,0+
0
Depth range
0–22 km
Earthquakes over time
Cumulative count · 89 earthquakes · total moment ≈ M1.9 · count moment
Depth (0 km at top). Grey: fixed depth.
Magnitude distribution
Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.
Earthquakes
146
Largest
M1.4
M3,0+
0
Depth range
0–22 km
Earthquakes over time
Cumulative count · 146 earthquakes · total moment ≈ M2.0 · count moment
Depth (0 km at top). Grey: fixed depth.
Magnitude distribution
Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.
Note: before February 2026 about half of events lacked an automatic magnitude, so magnitude-dependent figures (b-value, count of M≥X) under-count earlier periods — the catalogue is not homogeneous across this window. Cumulative moment is barely affected.
Earthquakes
344
Largest
M1.7
M3,0+
0
Depth range
0–22 km
Earthquakes over time
Cumulative count · 344 earthquakes · total moment ≈ M2.2 · count moment
Depth (0 km at top). Grey: fixed depth.
Magnitude distribution
Depth cross-sections — color by age (orange=newest, grey=older), point size by M. Rising cluster = possible magma intrusion.
Note: before February 2026 about half of events lacked an automatic magnitude, so magnitude-dependent figures (b-value, count of M≥X) under-count earlier periods — the catalogue is not homogeneous across this window. Cumulative moment is barely affected.
Earthquakes
1.202
Largest
M2.9
M3.0+
0
Days with data
562
This is a reduced view: it is built from the daily aggregate (counts, moment, magnitude bands, depth histogram) rather than individual events. Map points, the depth scatter, cross-sections and the migration fit are therefore missing — they need each event's location and depth. Counts, total moment and the b-value are exact, not approximated.
Earthquakes over time
Cumulative count and moment
Total moment of all events in the window equals a single Mw 3.3
Magnitude distribution
<1840
1–2101
2–314
3–40
≥40
Note: before February 2026 about half of events lacked an automatic magnitude, so magnitude-dependent figures (b-value, count of M≥X) under-count earlier periods — the catalogue is not homogeneous across this window. Cumulative moment is barely affected.
Earthquakes
2.369
Largest
M2.9
M3.0+
0
Days with data
1.194
This is a reduced view: it is built from the daily aggregate (counts, moment, magnitude bands, depth histogram) rather than individual events. Map points, the depth scatter, cross-sections and the migration fit are therefore missing — they need each event's location and depth. Counts, total moment and the b-value are exact, not approximated.
Earthquakes over time
Cumulative count and moment
Total moment of all events in the window equals a single Mw 3.4
Magnitude distribution
<11882
1–2219
2–321
3–40
≥40
Note: before February 2026 about half of events lacked an automatic magnitude, so magnitude-dependent figures (b-value, count of M≥X) under-count earlier periods — the catalogue is not homogeneous across this window. Cumulative moment is barely affected.
Earthquakes
4.066
Largest
M3.7
M3.0+
5
Days with data
2.113
This is a reduced view: it is built from the daily aggregate (counts, moment, magnitude bands, depth histogram) rather than individual events. Map points, the depth scatter, cross-sections and the migration fit are therefore missing — they need each event's location and depth. Counts, total moment and the b-value are exact, not approximated.
Earthquakes over time
Cumulative count and moment
Total moment of all events in the window equals a single Mw 4.0
Magnitude distribution
<13168
1–2567
2–369
3–45
≥40
Gutenberg-Richter b ≈ 0.98 ± 0.07 (i.e. likely 0.90–1.05, M≥1.7, n=135)
Note: before February 2026 about half of events lacked an automatic magnitude, so magnitude-dependent figures (b-value, count of M≥X) under-count earlier periods — the catalogue is not homogeneous across this window. Cumulative moment is barely affected.
Earthquakes
4.638
Largest
M3.7
M3.0+
11
Days with data
2.508
This is a reduced view: it is built from the daily aggregate (counts, moment, magnitude bands, depth histogram) rather than individual events. Map points, the depth scatter, cross-sections and the migration fit are therefore missing — they need each event's location and depth. Counts, total moment and the b-value are exact, not approximated.
Earthquakes over time
Cumulative count and moment
Total moment of all events in the window equals a single Mw 4.1
Magnitude distribution
<13340
1–2908
2–3121
3–411
≥40
Gutenberg-Richter b ≈ 1.01 ± 0.06 (i.e. likely 0.95–1.07, M≥1.7, n=250)
Note: before February 2026 about half of events lacked an automatic magnitude, so magnitude-dependent figures (b-value, count of M≥X) under-count earlier periods — the catalogue is not homogeneous across this window. Cumulative moment is barely affected.
Depth is automatic and uncertain; earthquakes alone do not show magma movement — deformation (GPS) and gas are needed. Grey points: automatic fixed-depth values. b-value computed for M≥1.5 (automatic magnitudes make lower completeness unreliable). Preliminary data.
Earthquakes in the system
| Time (UTC) | Mag | Depth (km) | Area |
|---|---|---|---|
| 2026-09-11 07:51 | M0.1 | 0.0 | Other areas |
| 2026-09-11 05:13 | M-0.4 | 0.0 | Other areas |
| 2026-09-10 16:33 | M0.1 | 5.2 | Other areas |
| 2026-09-01 05:56 | M-0.3 | 0.0 | Other areas |
| 2026-09-01 02:22 | M0.4 | 4.8 | Tjörnes / N-land |
| 2026-08-29 14:32 | M0.4 | 3.3 | Other areas |
| 2026-08-27 18:38 | M0.3 | 0.0 | Other areas |
| 2026-08-26 05:44 | M0.2 | 14.8 | Other areas |
| 2026-08-21 10:45 | M0.2 | 4.2 | Tjörnes / N-land |
| 2026-08-18 19:47 | M-0.3 | 1.0 | Other areas |
| 2026-08-15 16:37 | M0.1 | 4.7 | Other areas |
| 2026-08-13 18:58 | M0.7 | 3.4 | Other areas |
| 2026-08-13 15:45 | M-0.5 | 4.7 | Other areas |
| 2026-08-12 21:23 | M1.0 | 1.7 | Tjörnes / N-land |
| 2026-08-12 21:17 | M0.6 | 4.9 | Tjörnes / N-land |
| 2026-08-12 21:14 | M1.2 | 4.8 | Tjörnes / N-land |
| 2026-08-11 21:46 | M0.6 | 4.5 | Other areas |
| 2026-08-10 04:52 | M-0.5 | 0.0 | Other areas |
| 2026-08-04 23:33 | M-0.4 | 4.1 | Other areas |
| 2026-08-04 09:41 | M0.1 | 10.7 | Other areas |
| 2026-08-04 09:40 | M0.1 | 11.7 | Other areas |
| 2026-07-29 23:32 | M0.5 | 22.1 | Other areas |
| 2026-07-29 23:30 | M-0.3 | 8.2 | Other areas |
| 2026-07-25 19:50 | M0.6 | 3.7 | Other areas |
| 2026-07-23 10:18 | M-0.5 | 0.0 | Other areas |
| 2026-07-22 10:52 | M0.1 | 1.4 | Other areas |
| 2026-07-21 17:04 | M-1.0 | 0.6 | Other areas |
| 2026-07-21 08:33 | M0.4 | 5.0 | Other areas |
| 2026-07-18 15:32 | M-0.3 | 0.0 | Other areas |
| 2026-07-16 19:45 | M-0.6 | 5.5 | Other areas |
| 2026-07-10 23:18 | M0.3 | 0.0 | Other areas |
| 2026-07-01 04:09 | M0.6 | 15.7 | Tjörnes / N-land |
| 2026-06-29 23:45 | M0.1 | 8.7 | Other areas |
| 2026-06-29 08:34 | M-0.0 | 4.2 | Other areas |
| 2026-06-28 18:35 | M0.6 | 18.5 | Other areas |
| 2026-06-25 17:23 | M0.5 | 3.9 | Other areas |
| 2026-06-25 08:05 | M0.5 | 8.6 | Tjörnes / N-land |
| 2026-06-25 02:58 | M0.1 | 4.9 | Other areas |
| 2026-06-19 02:40 | M0.4 | 2.7 | Other areas |
| 2026-06-14 04:01 | M-0.4 | 1.5 | Other areas |
| 2026-06-13 19:57 | M0.9 | 4.2 | Other areas |
| 2026-06-13 19:54 | M0.4 | 3.6 | Other areas |
| 2026-06-13 09:47 | M0.1 | 0.0 | Other areas |
| 2026-06-13 09:44 | M1.3 | 4.6 | Other areas |
| 2026-06-10 23:19 | M0.4 | 4.5 | Other areas |
| 2026-06-10 23:10 | M1.1 | 3.8 | Other areas |
| 2026-06-10 19:27 | M0.2 | 4.7 | Other areas |
| 2026-06-10 19:09 | M1.1 | 3.5 | Other areas |
| 2026-06-10 16:07 | M0.7 | 4.2 | Other areas |
| 2026-06-10 12:46 | M1.1 | 3.8 | Other areas |
| 2026-06-06 12:26 | M-0.4 | 15.9 | Other areas |
| 2026-06-05 20:31 | M1.4 | 4.5 | Other areas |
| 2026-06-04 14:02 | M0.2 | 4.6 | Other areas |
| 2026-05-30 08:54 | M0.5 | 4.9 | Other areas |
| 2026-05-26 17:07 | M0.2 | 5.7 | Other areas |
| 2026-05-25 10:53 | M0.1 | 3.5 | Other areas |
| 2026-05-19 05:50 | M0.5 | 5.0 | Other areas |
| 2026-05-19 05:47 | M0.4 | 4.1 | Other areas |
| 2026-05-17 18:06 | M-0.6 | 1.8 | Tjörnes / N-land |
| 2026-05-11 00:58 | M0.4 | 8.2 | Other areas |
System journal
Automatic snapshots and media coverage, in chronological order. Subscribe: RSS · ntfy
skjalftar-theistareykir2026-08-13 02:25:05 UTC
Over the last 24 hours, activity has been increasing in the Þeistareykir volcanic system in the Northern Volcanic Zone, with 3 earthquakes detected, which is well above the weekly average rate. This represents slightly more activity than usual for this area, characterized by scattered background activity rather than swarms, as 92% of events over the last 7 days were independent. The largest earthquake in the last 48 hours was magnitude 1.4, and the cumulative magnitude for the period was Mw 1.5, although it should be noted that these are automatic preliminary results with unreliable depth. This activity most closely resembles the period around 1 May 2026, and further maps and trend data can be found below.2026-08-04 20:10:06 UTC
Over the last 24 hours, seismic activity in the Þeistareykir volcanic system on the North Volcanic Zone has been increasing, with 4 earthquakes detected, which is well above the weekly average rate. This represents slightly more activity than usual for this area, characterized by scattered background activity rather than swarms, as 97% of events over the last 7 days were independent. The largest earthquake in the last 48 hours was magnitude 0.4 and the cumulative seismic moment for that period was 0.7 Mw, although these results are automatic preliminary data with unreliable depth measurements. The current activity most closely resembles the period around July 2, 2026, when 9 earthquakes were detected in the area.2026-06-15 12:45:05 UTC
In the last 24 hours, three earthquakes were recorded in the Þeistareykir volcanic system, representing normal background activity for the area and similar to the past week. The activity is distributed rather than swarm-like and most closely resembles the period around August 10, 2025, though these are automatic preliminary results with unreliable depth. Further details on trends and maps are available below.2026-06-14 19:55:03 UTC
In the last 24 hours, three earthquakes were recorded at Þeistareykir, representing an increase above the weekly average and higher activity than usual for this area. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around June 11, 2025. The largest earthquake was M0.9 and the cumulative magnitude over the last 48 hours was Mw 1.1. Results are automatic preliminary results, and further data can be found below on the page.2026-06-14 15:35:03 UTC
In the last 24 hours, three earthquakes were recorded in the Þeistareykir volcanic system, a volcanic system on the Northern Volcanic Zone with geothermal activity, and activity is increasing compared to the weekly average but remains normal for this area. The earthquakes represent distributed background activity rather than swarms, and the largest earthquake in the last 48 hours was magnitude M0.9 with a cumulative moment of Mw 1.1. Activity most closely resembles the period around June 11, 2025, though results are automatic preliminary results. Further details on trends can be found below.2026-06-11 19:05:04 UTC
In the last 24 hours, six earthquakes were recorded in the Þeistareykir volcanic system, a geothermal area on the Northern Volcanic Zone, with activity now increasing and higher than usual for this region. The increase is characterized by distributed background activity rather than swarms and most closely resembles the period around June 11, 2025, though these are automatic preliminary results. The cumulative magnitude of earthquakes in the last 48 hours was Mw 1.8. Further details on trends and maps are available below.2026-06-11 16:10:05 UTC
In the last 24 hours, seven earthquakes were recorded in the Theistareykir volcanic system, indicating higher than usual activity for this area and an increase from the weekly average. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around June 11, 2025. The largest earthquake was magnitude M1.5 and the cumulative moment over the last 48 hours is Mw 1.8. These results are automatic preliminary results and further data can be found below.2026-06-11 12:50:07 UTC
In the last 24 hours, eight earthquakes were recorded in the Þeistareykir system, indicating higher than usual activity for this area and an increase from previous days. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around June 11, 2025. The largest earthquake was M1.5 with a cumulative magnitude of Mw 1.8 over the past 48 hours, and these figures are automatic preliminary results. Further details on trends and measurements can be found below.2026-06-10 23:15:04 UTC
In the last 24 hours, seven earthquakes were recorded in the Þeistareykir system, indicating higher than usual activity for this area and an increase from the weekly average. The activity is characterized by distributed background seismicity rather than swarms and most closely resembles the period around June 11, 2025. The largest earthquake was M1.5 with a cumulative magnitude of Mw 1.8 over 48 hours, and the b-value is 4.3. Results are automatic preliminary results, and further data can be found below.2026-06-10 19:10:05 UTC
In the last 24 hours, four earthquakes were recorded at Þeistareykir, representing an increase compared to the weekly average, though activity remains normal for this area. The events are predominantly scattered background activity rather than swarms, with the largest earthquake being M1.5 and a cumulative magnitude of Mw 1.6. These automatic preliminary results most closely resemble the period around June 9, 2025, in terms of event count. Further details and maps are available below.What do the numbers mean — and what should I do?
β (swarm signal): how high activity is versus the area's 2-year average. β above 2 means an ongoing swarm. It measures activity, not a forecast of a large quake.
Cumulative moment (Mw): the combined energy of the quakes in the period. Uplift (GNSS): whether the ground is rising or sinking, mm per year — the data are a few weeks old. Some systems (e.g. Svartsengi) deform in steps during eruption cycles rather than at a steady annual rate.
Swarm character is computed for a whole volcanic belt, not a single system — it describes the belt, not necessarily this one system.
What should I do? This is automatic monitoring for information — not an official warning. Follow official information from the Icelandic Met Office and Civil Protection (112).